In note 34 on page 28 of Ptolemy's Geography, J. L. Berggren writes:
He goes on to attribute this idea to H. Müller in 1837. Basically, the proposition is that Ptolemy's place name Siatoutanda, otherwise unknown, is actually a mistake based upon his having misread Tacitus' description of a trip "to ensure their safety" (ad sua tutanda) as a trip "to Suatutanda" (ad Suatutanda), with Ptolemy deducing from geographical context the approximate location of the town.
There is no hard evidence to support this idea: no archaeological remains (which would not be expected anyway if the town's name is a mistake), no ancient testimony to the effect that Ptolemy misread Tacitus here, no inscriptions to support the claim. It is just a very observant literary idea with very real historical consequences (that Ptolemy had read Tacitus, for one thing; that such a town never actually existed, for another).
Is this, in your opinion, good history? There is no way it measures up to anything resembling the standards of proof required in a courtroom (standards which historians admit are too stringent for the pursuit of ancient history anyway, though I am speaking of American law courts here, and things may be different in other countries); I doubt it would even measure up to standards of proof for plagiarism. Is it a good idea, in your judgment, for historians to float these kinds of ideas? Does it depend upon them admitting the speculative nature of the idea (thus implying that Jesus historians might well do the same)? Or should Müller have kept mum about even the very possibility until he had ironclad proof?
(Full disclosure: I have not read every single post on this thread, and have found the ones I have read, even early on when I had not skipped any yet, pretty confusing at times.)