Earlier quoted context omitted.
I think a similar argument can be made for the legacy of the indo europeans. You just have to go a bit further back, before greek and hittite and celt and iranian/aryan and vedic cultures where a distinct thing, there was one single culture speaking a single language: the proto indo european people and culture. They had a lot of success (horse drawn carts with wheels, bronze working). They slowly spread east and west…
> Vascon and Etruscan survived (and possibly others) How about Finno-Ugric? While the Hungarians only arrived about 1000 years ago, the ancestors of the Finns, Sami and related groups have lived in North-East Europe possibly since the last Ice Age (although this is much disputed, and it could be they adopted Proto-Finnic from some later migration).
However, as the article mentions, it's unwise to assume there is a 100% correlation between genetic markers and culture/language. The Baltic Sea region has been a trade hub since before the the first indo-european migrations into the area, and some genetic mixing must have been unavoidable.