And then there is other difficulty. The way Tertullian describes the beginning of the Marcionite gospel - and this goes back to the OP - the order is completely contradictory to what appears in Luke but also Mark and Matthew. Jesus descends from heaven to earth (most likely Jerusalem). Ephrem says Bethsaida. Luke's ordering of synagogue narratives in Nazareth and then Capernaum are inverted. Tertullian says the descent happens at Capernaum. Jesus heals the demoniac and then the stuff which precedes the healing in Luke comes after it and Jesus flies. Very little in the synoptics actually contradict one another. What we see in Luke actually contradicts the synoptic ordering (especially if Irenaeus and the Syriac fragments descent to Judea is factored in). But doesn't that make you suspicious that Luke is supposed to be the gospel of Marcion and the gospel of Marcion contradicts the synoptic ordering. It's almost as if the Marcionite gospel is the Mark that Papias says contradicts the ordering of Matthew, queen of the synoptics according to all standard orderings in antiquity. Notice also that Tertullian's Against Marcion pays special attention to improper ordering in the gospel of Marcion i.e. what is said when John appears suddenly:
From what direction does John make his appearance? Christ unexpected: John also unexpected. With Marcion all things are like that: with the Creator they have their own compact order.
Unde autem et Ioannes venit in medium? Subito Christus, subito et Ioannes. Sic sunt omnia apud Marcionem, quae suum et plenum habent ordinem apud creatorem. Sed de Ioanne cetera alibi. [11.4]
It is worth noting that Papias's interest in 'order' have a different sense in anti-Marcionite treatises - i.e. dispensation:
And indeed I do allow that one order did run its course in the old dispensation under the Creator,10 and that another is on its way in the new under Christ.
Atque adeo confiteor alium ordinem decucurrisse in veteri dispositione apud creatorem, alium in nova apud Christum.
and again:
You have now our answer to the Antitheses compendiously indicated by us. I pass on to give a proof of the Gospel38 ----not, to be sure, of Jewry, but of Pontus----having become meanwhile39 adulterated; and this shall indicate the order by which we proceed.
Habes nunc ad Antitheses expeditam a nobis responsionem. Transeo nunc ad evangelii, sane non Iudaici sed Pontici, interim adulterati demonstrationem, praestructuram ordinem quem aggredimur. [2.1]
The incorrect 'ordering' of Marcion's gospel is a sign of forgery:
In short, when Marcion laid hands on it, it then became diverse and hostile to the Gospels of the apostles. [7] I will therefore advise his followers, that they either change these Gospels, however late to do so, into a conformity with their own, whereby they may seem to be in agreement with the apostolic writings (for they are daily retouching their work, as daily they are convicted by us); or else that they blush for their master, who stands self-condemned134 either way----when once135 he hands on the truth of the gospel conscience smitten, or again136 subverts it by shameless tampering. Such are the summary arguments which we use, when we take up arms137 against heretics for the faith138 of the gospel, maintaining both that order of periods, which rules that a late date is the mark of forgers,139 and that authority of churches140 which lends support to the tradition of the apostles; because truth must needs precede the forgery, and proceed straight from those by whom it has been handed on.
Denique ubi manus illi Marcion intulit, tunc diversum et aemulum factum est apostolicis. [7] Igitur dabo consilium discipulis eius, ut aut et illa convertant, licet sero, ad formam sui, quo cum apostolicis convenire videantur (nam et cotidie reformant illud, prout a nobis cotidie revincuntur), aut erubescant de magistro utrobique traducto, cum evangelii veritatem nunc ex conscientia tramittit, nunc ex impudentia evertit. His fere compendiis utimur, cum de evangelii fide adversus haereticos expedimur, defendentibus et temporum ordinem posteritati falsariorum praescribentem, et auctoritatem ecclesiarum traditioni apostolorum patrocinantem, quia veritas falsum praecedat necesse est, et ab eis procedat a quibus tradita est. [5.6, 7]
The 'order' of his descent is problematic too. The synoptics of course have a dove come down but Marcion's gospel has Jesus himself descend:
In the fifteenth year of the reign of Tiberius155 (for such is Marcion's proposition) he "came down to the Galilean city of Capernaum," of course meaning from the heaven of the Creator, to which he had previously descended from his own. What then had been his order for him to be described as first descending from his own heaven to the Creator's? For why should I abstain from censuring those parts of the statement which do not satisfy the requirement of an ordinary narrative, but always end in a falsehood? To be sure, our censure has been once for all expressed in the question, which we have already157 suggested: Whether, when descending through the Creator's domain, and indeed in hostility to him, he could possibly have been admitted by him, and by him been transmitted to the earth, which was equally his territory? [2] Now, however, I want also to know the remainder of his order down, assuming that he came down. For we must not be too nice in inquiring158 whether it is supposed that he was seen in any place. To come into view159 indicates160 a sudden unexpected glance, which for a moment fixed161 the eye upon the object that passed before the view, without staying. But when it happens that a descent has been effected, it is apparent, and comes under the notice of the eyes.162 Moreover, it takes account of fact, and thus obliges one to examine in what condition with what preparation,163 with how much violence or moderation, and further, at what time of the day or night, the descent was made; who, again, saw the descent, who reported it, who seriously avouched the fact, which certainly was not easy to be believed, even after the asseveration.
Ecquid2 ergo ordinis fuerat ut prius de suo caelo in creatoris descendens describeretur? Cur enim non et ista reprehendam quae non implent fidem ordinariae narrationis, deficientis in mendacio semper? Plane semel dicta sint per quae iam alibi retractavimus an descendens per creatorem, et quidem adversus ipsum, potuerit ab eo admitti et inde tramitti in terram aeque ipsius. [2] Nunc autem et reliquum ordinem descensionis expostulo, tenens descendisse illum. Viderit enim sicubi appamisse positum est. Apparere subitum ex inopinato sapit conspectum, qui semel impegerit oculos in id quod sine mora apparuit. Descendisse autem dum fit, videtur et subit3 oculos. De facto etiam ordinem facit, atque ita cogit exigere, quali habitu, quali suggestu, quonam impetu vel temperamento, etiam quo in tempore diei noctisve descenderit: praeterea quis viderit descendentem, quis retulerit, quis asseveraverit rem utique nec asseveranti facile credendam. [7.1,2]
Tertullian makes reference to the improper 'order' in the Marcionite gospel with respect to healing of the leper:
On the same principle occurs all the rest. So far as renouncing all human glory went, He forbade the man to publish abroad the cure; but so far as the honour of the law was concerned, He requested that the usual course should be followed: "Go, show thyself to the priest, and present the offering which Moses commanded."261 For the figurative signs of the law in its types He still would have observed, because of their prophetic import.
Secundum haec cetera quoque occurrunt. Quantum enim ad gloriae humanae aversionem pertinebat, vetuit eum divulgare, quantum autem ad tutelam legis, iussit ordinem impleri: Vade, ostende te sacerdoti, et offer mvmus quod praecepit Moyses ... [9.9]
The reference again to the improper 'order' in the Marcionite gospel with respect to John:
Unde autem et Ioannes venit in medium? Subito Christus, subito et Ioannes. Sic sunt omnia apud Marcionem, quae suum et plenum habent ordinem apud creatorem. Sed de Ioanne cetera alibi. Ad praesentes enim quosque articulos respondendum est. Nunc illud tuebor, ut demonstrem et Ioannem Christo et Christum Ioanni convenire, utique prophetae creatoris, qua Christum creatoris, atque ita erubescat haereticus, Ioannis ordinem frustra frustratus.
The author implores Marcion to learn 'the proper order of the prophets' which is missing from his gospel:
Certe evangelizat Sion et Hierusalem pacem et bona omnia, certe ascendit in montem et illic pernoctat in oratione et utique auditur a patre. Evolve igitur prophetas, et ordinem totum recognosce.
Surely to Sion He brings good tidings, and to Jerusalem peace and all blessings; He goes up into a mountain, and there spends a night in prayer,423 and He is indeed heard by the Father. Accordingly turn over the prophets, and learn therefrom His entire course.424 "Into the high mountain," says Isaiah, "get Thee up, who bringest good tidings to Sion; lift up Thy voice with strength, who bringest good tidings to Jerusalem." [13.1]
The allusion to the improper 'ordering' of Marcion's gospel appears almost always at the head of each section. So in the next chapter:
Venio nunc ad ordinarias sententias eius, per quas proprietatem doctrinae suae inducit, ad edictum, ut ita dixerim, Christi: Beati mendici (sic enim exigit interpretatio vocabuli quod in Graeco est), quoniam illorum est regnum dei.
I now come to those ordinary precepts of His, by means of which He adapts the peculiarity454 of His doctrine to what I may call His official proclamation as the Christ.455 "Blessed are the needy" (for no less than this is required for interpreting the word in the Greek,456 "because theirs is the kingdom of heaven."457 Now this very fact, that He begins with beatitudes, is characteristic of the Creator, who used no other voice than that of blessing either in the first fiat or the final dedication of the universe: for "my heart," says He, "hath indited a very good word." [14.1]
Later the author complains that the Marcionite emphasis of love of the stranger is out of proper order:
For what man will be able to bestow the love (which proceeds from knowledge of character,591 upon strangers? Since, however, the second step592 in charity is towards strangers, while the first is towards one's neighbours, the second step will belong to him to whom the first also belongs, more fitly than the second will belong to him who owned no first.593 Accordingly, the Creator, when following the course of nature, taught in the first instance kindness to neighbours,594 intending afterwards to enjoin it towards strangers; and when following the method of His dispensation, He limited charity first to the Jews, but afterwards extended it to the whole race of mankind. [16.11]
The menstrual flow of the sinful woman was wrongly interpreted by the Marcionites as being out of order:
She therefore, not without reason,765 interpreted for herself the law, as meaning that such things as are susceptible of defilement become defiled, but not so God, whom she knew for certain to be in Christ. But she recollected this also, that what came under the prohibition of the law766 was that ordinary and usual issue of blood which proceeds from natural functions every month, and in childbirth, not that which was the result of disordered health. Her case, however, was one of long abounding767 ill health, for which she knew that the succour of God's mercy was needed, and not the natural relief of time. [20.12]
The example of David provides the proper 'order' of Christ:
If you also turn to the fourth book, you will discover all this conduct790 of Christ [ordinem Christi] pursued by that man of God, who ordered ten791 barley loaves which had been given him to be distributed among the people; and when his servitor, after contrasting the large number of the persons with the small supply of the food, answered, "What, shall I set this before a hundred men? "he said again, "Give them, and they shall eat: for thus saith the Lord, They shall eat, and shall leave thereof, according to the word of the Lord."792 O Christ, even in Thy novelties Thou art old! [21.2]
He speaks of Christ of the fourfold gospel reflecting the order of the Creator:
But if he was in error here because of his previous erroneous opinion,857 then you may be sure that up to that very day no new divinity had been revealed by Christ, and that Peter had so far made no mistake, because hitherto Christ had revealed nothing of the kind; and that Christ accordingly was not to be regarded as belonging to any other than the Creator, whose entire dispensation858 he, in fact, here described
Quodsi ideo et hic erravit quia et supra, ergo certus es in illum diem quoque nullam novam divinitatem a Christo revelatam, et usque adhuc non errasse Petrum, Christo usque adhuc nihil eiusmodi revelante, et tamdiu non alterius deputandum Christum quam creatoris, cuius omnem et hic ordinem expressit. [22.6]
The true gospel is 'orderly' because it accepts apparently the 'order of prophecy.'
Lastly, you may discover the suitable times of the promise, if you read what precedes the passage: "Be strong, ye weak hands and ye feeble knees: then the eyes of the blind shall be opened, and the ears of the deaf shall hear; then shall the lame man leap as an hart, and the tongue of the dumb shall be articulate."981 When, therefore, He proclaimed the benefits of His cures, then also did He put the scorpions and the serpents under the feet of His saints----even He who had first received this power from the Father, in order to bestow it upon others and then manifested it forth conformably to the order of prophecy [et secundum ordinem praedicationis exhibuit]
When his disciples ask him how to pray the issue of 'order' is brought up again and the Marcionite emphasis on a 'new order':
If, however, he had already learned this, prove it. If you find nowhere any proof, let me tell you1048 that it was to the Creator that he asked for instruction in prayer, to whom John's disciples also used to pray. But, inasmuch as John had introduced some new order of prayer, this disciple had not improperly presumed to think that he ought also to ask of Christ whether they too must not (according to some special rule of their Master) pray, not indeed to another god, but in another manner. [Sed quia et Ioannes novum aliquem ordinem orationis induxerat, ideo hoc et a Christo discipulus eius expostulandum non immerito praesumpserat, ut et illi de proprio magistri sui instituto non alium, sed aliter, deum orarent]
and again a few sentences later:
Who shall suffer us not to be led into temptation? He before whom the tempter will never be able to tremble; or He who from the beginning has beforehand condemned1059 the angel tempter? If any one, with such an order [hoc ordine] invokes another god and not the Creator, he does not pray; he only blasphemes.
Again Marcion's lack of reference to the Old Testament marks the gospel as being improperly ordered:
(Now, I ask, ) after going through all this course of the Creator's order and prophecies, what there is in it which can possibly be assigned to him who has done all his work at one hasty stroke,1273 and possesses neither the Creator's order nor His dispensation in harmony with the parable? Or, again in what will consist his first invitation,1275 and what his admonition1276 at the second stage? Some at first would surely decline; others afterwards must have accepted."1277 But now he comes to invite both parties promiscuously out of the city,1278 out of the hedges,1279 contrary to the drift1280 of the parable.
Quid ex hoc ordine secundum dispositionem et praedicationes creatoris recensendo competere potest illi, cuius nec ordinem habet nec dispositionem ad parabolae conspirationem qui totum opus semel fecit? Aut quae erit prima vocatio eius, et quae secundo actu admonitio? Ante debent alii excusare, postea alii convenisse. Nunc autem pariter utramque partem invitare venit, de civitate, de sepibus, adversus speculum parabolae.
The point here is since we don't now know in what way Mark 'was not in the correct order' - couldn't it have been in the way Marcion's gospel was repeatedly said to be 'out of order' - i.e. out of order with the old testament?
“Finally, from so little sleeping and so much reading, his brain dried up and he went completely out of his mind.”
― Miguel de Cervantes Saavedra, Don Quixote