All the migrations postulated by Renfrew ultimately stem from a single catalyst: the crossing of Anatolian farmers into Greece… For all practical pur… - Colin Renfrew

[Supporters of Renfrew’s theory] “have tried to render the Indo-Iranian problem moot. They argue that the Indo-Iranian branch was somehow divided from the main body of Proto-Indo-European before the colonists brought agriculture to the Balkans. Greek and Indic are thus separated by millenniums of linguistic change - despite the close grammatical correspondences between them (... these correspondences probably represent shared innovations from the last stage of PIE).”

This area [east Macedonia], although firmly now part of Greece, has sometimes been a marginal one, and may at times have owed allegiance in different directions through a process of boundary displacement. It was indeed occupied in early classical times by Thracian tribes, barbarians who did not speak the Greek language. No doubt they did indeed speak a Thracian language akin to that in what is now Bulgaria, whose origins were suggested earlier.

As far as I can see there is nothing in the Hymns of the Rig Veda which demonstrates that the Vedic-speaking population were intrusive to the area: this comes rather from a historical assumption of the "coming of the Indo-Europeans." .. Nothing implies that the Aryans were strangers there.