It seems like Germany is unpowered as well. I've seen them get stuck at one city two games in a row, to the point that the center of Europe is never settled, even up to 1750 AD. There are huge empty bits of territory that one one, not Austria, not the Norse, France, or Poland settles even though they are prime city spots. Very weird and unrealistic.
Maybe we could solve this by giving all civs a "replacement" civ, that can settle most of the territory if the original civ is destroyed or very weak. Logically, Hungary and Austria could be each others; Genoa and Venice; Arabia and Cordoba even. These "replacement" civs can settle these territories, although they aren't very aiming to do so, because the settler value should be low.
So, when Germany is weak or even destroyed quickly, then France, the Norse, Austria and even Poland could slowly claim some parts of Germany. Also, this makes a respawn more likely. It wouldn't happen if Germany stays alive, since the settler values are so low. Only when there is nowhere to expand and there is some unoccupied territory, then the civ could decide to settle there.
Is this ahistorical: in theory yes, but in practice the difference would often be small. Also, remember that e.g. the Germans "colonized" large parts in Eastern Europe, small parts of Europe still have German as their native language.
I do have a question though: is it possible to make settler maps dynamic? If Germany is alive and kicking, then the Dutch wouldn't there, but if Germany is gone, the only logical step for them would be to claim the land theirselves.
Both ideas have the similar effect, I don't know which is best to implement (if any of them is good enough of course

).