Before Napoleon, were there something like 300 dukedoms and duchys and princpates and such? One of the guys I taught with had family in Germany - somewhere - and he spoke fluent German. However, many of our German exchange students couldn't understand him.Well, that makes sense....Austrian Germans are different from other Germans. Just ask a German.
But then, EVERY part of Germany thinks that of every other part.
Some of them can't even understand each other's version of daily spoken German.