Some very fascinating stuff, indeed. Thanks for the great write-up.
Firstly, I just felt the need to clarify the Hurro-Urartian/NE Caucasian connection because I feel that there has been a lot of misrepresentation of that due to nationalism. I do think Wikipedia is at least partially to blame.
As for the Balkan model of Armenian migration, I have a lot of issues with it. If it did occur, it would have had to have been during or before the Bronze Age Collapse (which is what Diakonoff suggests). But, besides Herodotus (and maybe Strabo?) there's no mention of Armenians coming from the Balkans. It doesn't exist in Armenian legends, it doesn't exist in the genetic input from the time in question (supposedly the Armenian ethnogenesis
concluded by 1200 BCE according to the
Nature genetic study from a few years ago), and the pottery culture doesn't support an expansion from the west reaching anywhere near Armenia (so if they came from the west and expanded further east than Cappodocia, which they would have had to have done, they would have had to adopt a new pottery style fairly quickly). Herodotus himself relies on clothing or weaponry as evidence of a Phrygian connection, but it seems that some of these conventions were widespread in greater Anatolia at the time. Additionally, Herodotus also claims that the Persians and Medes come from Perseus and Madea (?), which could mean that he asserted the Iranians came from Greeks too, something that no modern scholars believe.
There was an expansion FROM the South Caucasus into the interior of modern Turkey (at least as far as Elazig) during the Bronze Age Collapse, as well as significant settlement from this eastern population (with estimates of up to 50% of an increase in South Caucasus-derived populations into Turkey). According to the Assyrians, these Caucasian migrants were the Urumu (which could be read as Arama, suggesting an Armenian element), Mushki (likely Indo-European, this is the group that Diakonoff connected to the Proto-Armenians), and the Kaskas (possibly Hattic or Caucasian). These groups settled in lands that would form the nexus of Armenian culture some centuries later. People tend to focus on the western ceramic ware (the so-called "Phrygian" ceramics) but don't pay attention to the "Transcaucasian" ceramic ware.
Genetics suggests that the Mycenaeans were Minoans+a probable Indo-European element from MLBA Armenia (as in the study I linked in my previous post). It would stand to reason then that since the Mycenaeans were IE (whereas the Minoans were not) that their Indo-European language was likely introduced by the Armenian-like people, and since the Armenian and Greek languages are connected, that the Armenian language was being spoken in Armenia by this time as well (probably in the Trialeti-Vanadzor Culture), which is Hamp's model (although he doesn't specify Trialeti-Vanadzor as Proto-Armenian).
Personally, I think it was something like Catacomb=Armenian/Greek/Phrygian/possibly Balkanic. Armenians/Greeks/Phrygians went south (Pontic Indo European=Greco-Armenians). Paleo-Balkanics may have gone north or south. Armenians/Greeks/Phrygians (and I suppose Macedonians if they were indeed a separate language and not a Greek dialect) broke off in the Caucasus or NE Turkey somewhere with Armenians remaining, Greeks/Macedonians moving westward, and Phrygians moving westward with the Greeks/Macedonians, but not as far west, the Phrygians would have stopped in Cappodocia or Troy.
This article explains what I'm talking about well:
http://smea.isma.cnr.it/wp-content/uploads/2016/02/Kossian_The-Mushki-problem-Reconsidered.pdf
Hamp's model (see page 13):
http://sino-platonic.org/complete/spp239_indo_european_languages.pdf
On Artemis:
https://pies.ucla.edu/IESV/1/VVI_Horse.pdf