A more detailed dissection of the relevant texts:
Mark 2:21 Οὐδεὶς (No one) ἐπίβλημα (a patch) ῥάκους (of cloth) ἀγνάφου (unshrunk) ἐπιράπτει (sews) ἐπὶ (on) ἱμάτιον (clothing) παλαιόν (old); εἰ (if) δὲ (now) μή (not) αἴρει (tears away) τὸ (the) πλήρωμα (patch) ἀπ’ (from) αὐτοῦ (it), τὸ (-) καινὸν (new) τοῦ (from the) παλαιοῦ (old), καὶ (And) χεῖρον (worse) σχίσμα (a tear) γίνεται (takes place).
22 Καὶ (And) οὐδεὶς (no one) βάλλει (puts) οἶνον (wine) νέον (new) εἰς (into) ἀσκοὺς (wineskins) παλαιούς (old); εἰ (if) δὲ (now) μή (not), ῥήξει (will burst) ὁ (the) οἶνος (wine) τοὺς (the) ἀσκούς (wineskins), καὶ (and) ὁ (the) οἶνος (wine) ἀπόλλυται (will be destroyed), καὶ (and) οἱ (the) ἀσκοί (wineskins). ἀλλὰ (Instead), οἶνον (wine) νέον (new) εἰς (into) ἀσκοὺς (wineskins) καινούς (new).”
Matthew 9:16 Οὐδεὶς (No one) δὲ (however) ἐπιβάλλει (puts) ἐπίβλημα (a patch) ῥάκους (of cloth) ἀγνάφου (unshrunk) ἐπὶ (on) ἱματίῳ (clothing) παλαιῷ (old); αἴρει (tears away) γὰρ (for) τὸ (the) πλήρωμα (patch) αὐτοῦ (of it) ἀπὸ (from) τοῦ (the) ἱματίου (garment), καὶ (and) χεῖρον (a worse) σχίσμα (tear) γίνεται (emerges).
17 Οὐδὲ (Nor) βάλλουσιν (pour they) οἶνον (wine) νέον (new) εἰς (into) ἀσκοὺς (wineskins) παλαιούς (old); εἰ (if) δὲ (now) μή¦γε (lest) ῥήγνυνται (are burst) οἱ (the) ἀσκοί (wineskins), καὶ (and) ὁ (the) οἶνος (wine) ἐκχεῖται (is poured out), καὶ (and) οἱ (the) ἀσκοὶ (wineskins) ἀπόλλυνται (are destroyed). ἀλλὰ (But) βάλλουσιν (they pour) οἶνον (wine) νέον (new) εἰς (into) ἀσκοὺς (wineskins) καινούς (new), καὶ (and) ἀμφότεροι (both) συντηροῦνται (are preserved).”
Bold and
italic denote the same, they're just different so the parts are smaller and easier to compare.
The purple is an addition by Matthew
What is not emphasised is particular to either Mark or Matthew, the remainder is verbatim agreement.
Either Mark copied Matthew here or the other way around, and while Mark's Greek is cringing such is generally the case so it won't serve as an argument here.
Mark's overexplaining such as τὸ (-) καινὸν (new) τοῦ (from the) παλαιοῦ (old) is likewise noted, and likewise it's typical for Mark, and likewise it doesn't attest to anything particular for this logion.
Are there textual elements that give away priority here? Matthew using ἐπιβάλλει for the patch / cloth is odd and reminiscent of the βάλλει he uses for the wine / skins, which is equally odd as the verb literally means 'to cast, throw' yet it's the favourite verb of our Romans with hundreds of occurrences all over the NT
Luke will be next:
Luke 5:36 Ἔλεγεν (He was speaking) δὲ (now) καὶ (also) παραβολὴν (a parable) πρὸς (to) αὐτοὺς (them) ὅτι (-): “Οὐδεὶς (No one) ἐπίβλημα (a piece) ἀπὸ (of) ἱματίου (a garment) καινοῦ (new) σχίσας (having torn), ἐπιβάλλει (puts it) ἐπὶ (on) ἱμάτιον (a garment) παλαιόν (old); εἰ (if) δὲ (however) μή¦γε (otherwise) καὶ (also) τὸ (the) καινὸν (new) σχίσει (he will tear), καὶ (and) τῷ (the) παλαιῷ (old) οὐ (not) συμφωνήσει (will match), τὸ (which is) ἐπίβλημα (the piece) τὸ (-) ἀπὸ (of) τοῦ (the) καινοῦ (new). 37 Καὶ (And) οὐδεὶς (no one) βάλλει (puts) οἶνον (wine) νέον (new) εἰς (into) ἀσκοὺς (wineskins) παλαιούς (old); εἰ (if) δὲ (now) μή¦γε (otherwise), ῥήξει (will burst) ὁ (the) οἶνος (wine) ὁ (-) νέος (new) τοὺς (the) ἀσκούς (wineskins), καὶ (and) αὐτὸς (it) ἐκχυθήσεται (will be spilled out), καὶ (and) οἱ (the) ἀσκοὶ (wineskins) ἀπολοῦνται (will be destroyed). 38 ἀλλὰ (But) οἶνον (wine) νέον (new) εἰς (into) ἀσκοὺς (wineskins) καινοὺς (fresh) βλητέον (must be put). 39 καὶ (And) οὐδεὶς (no one) πιὼν (having drunk) παλαιὸν (old wine) θέλει (desires) νέον (new); λέγει (he says) γάρ (for), ‘Ὁ (The) παλαιὸς (old) χρηστός (better) ἐστιν (is).’”
But for now, it seems blatantly evident that the above two fragments are copies of one another (or of a different and identical text, sure)
