WOW!!! A PhD dissertation (or two, or ten or twenty).
Fascinating stuff. I think recent historians of antiquity (Europe) have been overdoing the ethnography and "ethnogenesis" themes. We can only assume most of this, even from the archaeology.
Zosimus IIRC, and more certainly Ammianus Marcellinus understood Barbarian peoples in terms of gens
, or clans grouped together by some common descent.
Herwig Wolfram tends to divide the broad groupings of clans into tribal identities depending mostly on their last known origins. I.e., the "west Goths" came to Roman attention as "forest people" from west of the Steppes. The broad clan grouping known by the name Tervingi eventually became known as Vesi or Visigothi
The "east Goths" came from the steppes north of the Black Sea, being a clan grouping known as Geutrungi (no clue where that came from). They were Goths "glorified by the rising sun," according to Wolfram. The sun rises in the east, so - Ostrogothi
When such a division may have been recognized is an open question. These broad Barbarian tribal identities were known in the third century by a number of different names, but they were all still considered Scythians AFAIK - they were too far from the Limes Germanicus
at that time I suppose. It seems that once they were all more or less inside the Empire, they were just known as Goths for some time.
Salah, I wish I knew more about the cultural evidence in the recent archaeology, but I am too far along in life to pick up another complex interest.
It seems from historians Guy Halsall and Peter Heather, who both claim some archaeological understanding, that there is much data from recent decades of excavation and analysis. I suppose you can read their work and see if you agree.
Whatever any of us think we know about the Goths, a great deal of it is still going to be conjecture. They had runes, I think, but that sort of evidence is not really a record of anything, and using it as such is problematical at best. otherwise, they left no written record of their own until Ulfilas. As we all understand, Christian sources of the time concentrate mostly on the miracles of conversion, etc.
What we do know and understand is that these people were tough and impressive. They were adaptable and obviously intelligent within their limits. (The tough part was more useful when they wanted to make a statement to Roman authority.)
Their arrival on the historical radar trumps the Huns any way you want to analyze it.
You could discuss this forever and in dozens of directions if you want an academic career.