the problem with Thomas is that the community that wrote it was not connected with the other communities of Xy.
I'm become quite skeptical extremely quickly when NT scholars start talking about the community or communities behind some text or "layer" of a text. True, we're in a better position here than with Q (we actually have Thomas), but for me most of this type of scholarship is the unfortunate continuation of form-critical approaches to texts while in similar fields (and for many NT scholars) the research on orality has fundamentally changed the assumptions underlying the practice and methods used to refer to "Q communities" or the "early Thomas community". Thomas, even more than Q, is about as close to oral tradition as literature/writing can get:
"It has not been possible to detect consistent organizational devices by which the entries of the Gospel of Thomas (GT) were arranged into an intelligible sequential order. The majority of the 114 sayings and parables in the GT stand as isolated units, with only some of them constituting brief clusters of sayings. This lack of an overall thematic arrangement weighs all the more heavily since, as we have seen, Q is organized into larger clusters or discourses. The GT has placed all information units one next to the other with only minimal linking strategies and devoid of subordinate devices"
Kelber, W. H. (2006). The Verbal Art in Q and Thomas: A Question of Epistemology. In R. A. Horsely (Ed.)
Oral Performance, Popular Tradition, and Hidden Transcript in Q (
Semeia Studies). Brill.
You've read enough mythicist threads here to know that one of the go-to arguments is Paul's statement that he didn't receive the gospel from any man, implying (so the incorrect argument goes) that all he knew about Jesus came from revelation. This is anachronistic. It projects our concept of gospel (i.e., a biographical-type narrative about Jesus) onto what was then really just the joyous tidings that constituted the heart of the Christian message. In other words, it need not have meant anything about Jesus' ministry and for Paul it certainly didn't ("if Christ is not risen then we proclaim [our proclamations are] in vain, and so too is your faith").
You are also probably aware of Papias' remarks on where he received his information. So we are dealing in a time and with cultures that rely overwhelmingly on oral transmission and tradition. Cross-culturally, communities in which some oral history or oral tradition is more or less controlled (in NT studies, this would include models like Gerhardsson's, Bailey's, Byrskog's, and others), there is usually almost an inverse relationship with the extent to which parts of it are written down and how controlled it is (and usually by extension how important). Consider how long it took before there was a written version of the "oral torah" . Christianity differed in no small part because of a lack of closed communities that typically exist when there is some defining oral tradition for that community. Christian communities were more open, more receptive to exchanges of information (indeed, often defined by such exchanges, even among some so-called gnostic groups). Different Christian communities didn't just rely on differing collections of texts (if they had any), but most likely used these texts for formulate a body of orally transmitted material or even incorporated them into an already existing oral tradition:
"The
Didache lacks the narrative frame of Matthew and Luke, and the blessings and curses remain only in vestigial form. Nevertheless, it emphasizes the element of choice posed by the Deuteronomic tradition with the way of life and the way of death. In Thomas only fragments of this tradition remain, and the gospel uses the tradition more as the starting point for the creation of existential reflection to destabilize the world of the individual and lead on to
gnosis. While the fundamental covenantal register remains constant, the beginnings of divergence can also be seen, relating to the different contexts of the various performances"
Draper, J. (2006). Jesus’ “Covenantal Discourse” on the Plain (Luke 6:12–7:17) as Oral Performance: Pointers to "Q"as Multiple Oral Perfomance. Same volume as above.
Thus the idea that a document like Thomas, which survived in more than one manuscript when most of what remains of ancient writings isn't from fragments of texts but from quotations, and which was translated in order to facilitate the transmission of its content into other communities in which Greek was little known or not known, somehow can be deconstructed into one or more communities seems to me to be both baseless and contrary to the evidence we have.
Like Q, it likely was orally-transmitted for years before it was ever written down. It simply was not available at the time of canonization. Additionally, we have to remember that the canonization process wasn't meant to be the "be-all-end-all" we take it for today
I'm not sure what you mean by "the canonization process wasn't meant to be the 'be-all-end-all' we it for today", but as Thomas was written in my view around the time that the earliest proto-canon we know of existed (Marcion's), the canonization process hadn't really begun at all. Like you said, Thomas was orally transmitted for years, and in the wider context of a missionary Christianity. Thus parts of it were almost certainly used by multiple communities before it was ever written down, and after it was both the oral tradition and the written tradition were almost certainly circulated among communities (the written tradition we know was, as there isn't any other way to explain its translation into Coptic).