I'm still confused about PIE cradle:
we have to take in consideration:
What languages appeared in first writings in Near-East? Hittites and others cousin languages appeared very lately, it seems (Anatolian IE seems a bit strange, a medley?).
Between what ancient languages or proto-languages can we put the PIE, geographically and linguistically?
How can so much languages be born in the same restricted area (I know mountains can create isolats but...) - a proto-language to create "novation" (phonetical and grammatical separation and cristallization in a new very different form) needs strong isolation and a bit of time too, even if isolation can fasten things. PIE would have been a very structured language, of its own.
How can a zinc region receiving from all parts, men and words, and Y-ligneages (G,J,R1a, R1b, why not E,T,H? could produce a lot of tribes of almost only R1a, R1b, in a so short time, with this kind of language? I've doubts, even if I cannot be sure of anything.
Gutians, Sumerians: I don't know how many words and sentances we have of them but I find weird we can consider them as PIE only based upon a few unsure links, when we can suppose the very strong unity of reconstructed PIE. Northeastern Near-Eastern could be the cradle of IE but then at an old proto-proto-IE, not PIE stage: the true birthplace of OUR PIE would elsewhere, more Northeastern yet, I think (South-Central Asia, East the Caspian?)
That said, the today satem statut of Indo-Iranic languages could be linked to reintroduction from North-East at the late Steppic stages after a period in Steppes, Eastern European ones included <> I 've the impression ingredients for satemization were stronger in Eastern Europe than everywhere else. So, possibility for proto-centum dialects soon enough in Eastern Caspian regions before indoeuropeanization of Europe-West Asia with a third stage in East-Europe/West Asia giving way to satem languages?
only questioning and speculations.