Let's consider the following alt-WWI scenario:
the Central Powers barely wins WWI, but the Austrian-Hungarian Empire gets so weakened that it is divided in the aftermath of the War. An independent 'German' Austria state (maybe still including Slovenia?) emerges, maybe still ruled by the Habsburgs. This new 'German' Austria successfully lures the southern Catholic states of the German Empire (Baden, Württenberg, Bavaria etc.) to its own sphere, to the point of breaking the German Empire, maybe creating a northern one (centered in Prussia) and a southern one (centered in Austria). Maybe if some kind of supranational organization under German influence had been created for the control of the East (i.e. Mitteleuropa), the division of the Empire in two would not be that dramatical if both parts remain as co-leaders of that regional sphere.
IOTL the defeat of the CP prevented any kind of merge or reorganization of the German/Austrian states until 1938. But in a CP-win scenario nobody could prevent it if the involved states want to do so.
Habsburgs and German Austrian half minus Polish lands would just get integrated into German Empire. This actually puts Habsburg in more influential along with Catholic coalition of German people and monarchs against Prussian dominance of German Empire. Bohemia is likely added to German Empire too. Slovakia is given to Hungarians.
The former Austrian Empire would just be German puppets under a Habsburg monarch. Hungary, Transylvania, Banat(German enclave state that is largely self governing but due to regime dependence to Germany), and Poland are all made client kingdoms to German Empire. The German monarch and regimes there protect local German minorities and elevate them to rather protected and even privileged status.
With Balkans they might just give Bulgarians all of Serbia and even Bosnia just to not deal with it. Or back creation of Greater Croatia out of Bosnia and Croatia. Hungarians likely start issues and rebel down line at some point which sees Germany come in on behalf of Austrians to crush them. They take Croatia away as punishment and make Transylvania its own nation. They don’t give Transylvania to Romania. Transylvania is multi ethnic nation of Germans(most influential group), Hungarians, and Romanians under Habsburg German monarch.
Poland gets Austrian Poland and much of Poland out of former Russian Empire except the bits it gives to Baltic Union German client to north. I doubt Jews in Pale Settlement would prefer Poland to German ran Baltic Union state(Estonia, Lithuania, and Latvia including much of Pale Settlement and Congress of Poland panhandle area). Jews likely are one of more supportive local elements to German domination in region. This might give them more leverage on requests. The Polish monarch is likely Habsburg too due to being Catholic nation while Baltic Union has Protestant German prince as its monarch instead.
The situation with Croatia might be more complex bit for Germans and depends on what Italy did during war and after. If Italy just stayed neutral the Austrians/Germans are in better position and when the Austrians do fall apart, which even in wank CP victory is not out of question a decade or two if not less, they probably just given them Dalmatia and Albanian. Hell even if Italy flip sides near end and had regime change after poor performance in war as long as new regime is not radical or socialist the Germans might try to play “benevolent” role towards Italy over “forgiving” them over previous regime not joining war and still offer above with Austrians fall apart simply due to them not fearing Italy at all. They just make them renounce Istria and south Tirol claims.
The monarch is probably overthrown if Italy loses by joining allies and used as scapegoat by politicians. Aristocrats also used as justifiable scapegoat due to them being dip shits and stubborn with how they led armies to their death during war in mountains.
Italy status is important for Croatia because it might decide if they exist or not when Germany is deciding post war map. If Italy is given Dalmatia they likely let Hungarians keep its part of Croatia even if after they rebel while giving Bosnia to Bulgarian lead Yugoslavia that forms more out of Slavic lands and former Serbia to south.
Also Germany could possibly say screw it and just keep Croatia and Dalmatia while Bulgarian control inland
