[thaumasiotes]

Do you think I'm misunderstanding something other than that I'm not drawing the same distinction between proto-Germanic and "paleo-Germanic" that that paper appeals to?

You've quoted something that says after proto-Germanic had diversified, daughter lineages left southern Scandinavia to establish themselves elsewhere in the world.

But I pointed out a completely different idea in the paper, that before proto-Germanic diversified, about 2000 years before the time you mention, its speakers arrived in Scandinavia from "the northeast coast of the Baltic".

[HeinzStuckeIt]

Your post above wrote “the location of the proto-Germanic speakers”. Terminology matters; Proto-Germanic is something strictly defined as to what it was, with a longstanding consensus about where and when it was. If you wanted to talk about pre-Proto-Germanic speakers (or “Paleo-Germanic” speakers as this paper does, though I suspect some would quibble with that term used for a very early date), then you could have done so.

Moreover, you posted about a “new theory”, but the paper here only gives new evidence for an old theory.