Well, I think I see where we disagree. You seem to have a concept of Germanic expansions as including largely R1b-U152 peoples, with I2a2a peoples being Paleolithic remnants until quite late who were overrun by these R1b-U152 Germanics who then continued onto Italy. Correct me if I'm wrong here.
Yes, you would be wrong as pertains to your portrayal of my stance, or I did a really bad job of explaining my position.. one or the other.
Under my entire scenario, I am suggesting that the Getae/Massagetae are the Goths/Lombards/Gepids/Heruli etc.. who arise from the same homelands after the Getae disappear from history in that region,
and are effectively a eastern-germanic population that is long native to the eastern steppes, and never originated from or went to Scandinavia. Thus they are not ethnically 'Germanic' in the same modern, familiar sense of modern Scandinavian or Western German U-106, nor do I feel that U-152 relates to the origin of those western Continental or Scandinavian germanic cultures, or to modern "Germany" as a landmass.
I think a significant pct of U-152 get dispersed in some of these continental regions as the Goths are dispersed into the local populations in large numbers, especially in and around Chalons where they composed the majority of the fighting force that defeat the Huns.
In my opinion this residual U-152 is wrongly termed "Belgic" in and around this region, when it is a fairly minor component of all these regions Belgic of otherwise, even within the local R1b.
(To the ire of many I1 Hg, I am also pretty certain that I1 is effectively a 'Svearish' Hg, since R1b only arrives in Finland after the Svearish domination of Scandinavia, and is not followed to Finland by any U-106/R1b from Scandinavia where it comprises 1/3 of the population, since that R1b/U-106 is probably 'Geatish' and was then a recently subjected population to the I1 Svears-
I1 thus is not 'germanic' in the sense that it is the orginator of the culture, and we do not know where or when the Svears come into Scandinavia.)
The Getae/Getic name is used interchangeably by many ancient historians for the Goths and related tribes,
and this is only refuted by those who note that other ancient sources cite the Dacians/Illyrians and Getae reportedly 'speaking the same language'.
A ancient greek or roman observer - who is not fluent in either dacian/illyrian or german/gothic- seeing these parties conversing has no idea who is conversing in the others language, or what pct of the population(s) would have such skills even if they could decipher the languages.
The Dacians and Getae obviously are recorded as cooperating with one another, and some or even most would potentially be converstationally bi-lingual, in the same way that a Alan or Slav later in history (all of whom natively speak different languages) cooperate with the Lombards in Italy, not because they are the same ethnic population or the same Language families, but because portions of their populations are bi-lingual and able to mutually converse.
I am not in any way suggesting that U-152 = western-Germanics as would comprise the extant Germanic populations in western europe. They are a early germanic cultural offshoot that stayed in the east, and began migrating west for the safety of other europid populations once they became largely subjected in the east.
At this point in history even the Alani/Alans are recorded as blonde europids, but many generations later in Europe are asiatics/Hunnic in appearance, by greek and roman sources.
So.. those who were of a europid phenotype on the steppes at this point in history faced a 'migrate, die or be enslaved' option.
As the Migrating steppe germanics reach the west, they create and tell myths with the assistance of their new neighbors to explain who they are and how they got there, which is why the myths of the Goths and Lombards are essentially the same.
In a nutshell, U-152 is a steppe population of germanic linguistic background and in some ancient disconnected form, culture, that moves east as it becomes overwhelmed in its homelands, and it has been known to history for a long time by a variety of tribal names and historical mentions. (my theory!)
As to I2, I simply see no reason at this time to place it anywhere outside of europe, and it is in no way restricted to any celtic, germanic, slavic, or mediterranean population, its found across all of them,..
and not found in any non-european setting, so the best explanation is a aboriginal population that falls to the R1a/R1b populations and in some places manages to hand on or become adopted into those various cultures.
My own mothers' paternal line is Hg I2 from Scotland BTW, and its a very notable and important clade especially in ancient remains, where I2 and G2 appear to have played a very strong role early on in Europe. There is simply no reason, evidence, or basis to attach the origin of I2 to any of the arriving cultural groups though for all the above reasons.