Not sure about the handling of Germanic languages. It seems to me they'd survive better on the periphery, like in Britain and Scandinavia, rather than in the heart of the continent, much as the Celtic languages survived in insular environments IRL. German would probably have been an endangered language at this point: the invaders would be arriving in Europe at a time when the Holy Roman Empire was at its maximum extent, and Latin was at maximum prestige, so only peasants spoke MHG at the time (not OHG—that would've transitioned mid-11th millennium due to a major sound shift.) Remember, Mozart's operas (some 500 years later) were considered against the grain because they were in German.
(Alternatively, you may be subtly trying to block Rome proper from expanding into Germania when it did. Why not go the whole way and make Basque country cover the whole Iberian, then?)
Apologies if any of the above is eye-rollingly obvious. I have no clue what your credentials are when it comes to Germanic languages.