That’s a very good summary of the Balkans. Whenever I try to explain it, I usually get bashed for being Pro-Muslim/Serb/Croat by somebody, maybe I should just link to your post from now on!
I think Yugoslavia is a good example of what Germany could have been if it was more politically fragmented and a looser “German” identity existed. People might ask, “Are Bavarians and Prussians the same people?” You might have the same kind of ethnic nationalism with accusations that “Austrians are Catholic Prussians!”
last year I went to Augsburg and I find that the south of Germany is culturally quite distinct from the north.
you are right about comparing the Prussians and the Bavarians (though the Prussians don't exist any more :-P)
hoewver, in the case of Germany, Poland, Belarus, Lithuania and Romania, World War II eradicated those regional differences because millions were just eliminated and the remainder were forcibly mixed
I argue with my Polish wife that now Poland is one people, one religoin etc. but before WWII it was only 68% polish :)
In Poland's case, the communities of Poles in Lwów and Vilnius were simply pushed west -- in some cases to the opposite end to "reclaimed lands" -- reclaimed from Germany
And the Germans, who dreamed of Leibensraum, got the exact opposite -- Baltic Germans who had been living in the Baltics for 7 centuries, were eradicated as was Prussia and the Sudenten Germans
Germans from Romania, hungary etc. were sent to Germany even though they and their great-grandfathers had never seen that land. The mixing of peoples really created one "Germany"