Good Lord, guys, look at the shape of those Länder! Baden and Wurttemberg united? Hanover split? Prussia dismembered, with much of its core territory ceded to foreign powers? Berlin got some weird kind of 'free city' status (and how does Hamburg get to swallow up Altona, but not the Lübeck corridor?)
Losintg the Great War alone is not going to do that. Neither is a Fascist takeover. Remember, Fascists believe in traditional identity politics. I'm thinking, this could either be the result of an earlier POD, or a later deliberate policy of emasculation.
Think 1848 - the German rebels are successful with the aid of Polish insurrections stopping Russian troops from entering Prussia and binding large contingents that could otherwise interfere with the German revolutions. This new map is drawn by the victorious Rebel government ruling the country from - where? Frankfurt? Anyhow, it is fairly obvious that the Southwest was rewarded - retaining many of its original frontiers. Berlin, Hamburg and Bremen, with great sympathies for the revolution, were also given expanded borders and free status (Altona must have been thrown in when they took Schleswig-Holstein from Denmark, maybe as an exercise in national unity creation? Nothing like a good war to stir patriotic spirits), while Prussia was dismembered and large areas ceded to the Polish allies. The rhenish states got merged into this 'Nordrhein' monstrosity (I can't see how that would ever work - the Catholics and Protestants hate each other's guts down there!). Lübeck, traditional and conservative, is just swallowed up and dies. But whatz on earth could have moved them to create this Saar enclave? Is this supposed to be the relic of some kind of border dispute with France?
Alternatively, maybe this was the attempt by a foreign power to deliberately 'Swissify' Germany? Every state that could have expansionist intentions was artificially destroyed. Most obviously, Prussia is gone. Austria is reduced to the size of Switzerland, and it seems Bohemia and Moravia also went separate ways. Nordrhein-thingy has the heavy industry, but no ports or recruitment bases. Major urban and maritime centres have been cut out of large states (that may explasin the Saar - with that kind of mining and heavy industry, Baden-Wurttemberg might one day develop ambitions). Large agriculturalised surface states are separated from cities and industries. Bavaria got off liughtly, it seems, but they are ringed around with neighbours of similar size and power, and without a major industrial base. I don't see how, though. This wouldn't just require a defeat, it would require utter humiliation - little short of a colonial regime. Doubtlessly the French would like to, but there is no way they would be strong enough, and why leave the major powers near the French border? - no, not the French. It must have been the Russians! Some kind of major Russian victory, and they leave Germany in no state to ever attack them again before retreating (probabnly on British pressure). It still dioesn't explain Poland, though - except, maybe, given all that German territory, Poland must forever depend on Russia for its safety. Even this rump Germany could whip them anytime.
Life in this new statelet must be awful, though. The government in perpetual gridlock, the middle states riven by confessional dissent and the cities in conflict with the surface states. It's probably also quite poor, maybe even starving, given it's lost its most productive lands in the East. Was that the idea behind this ATL? Create something like a German 'Ireland'? I could see Nordrhein-thingy (I am fascinated by that monster, honestly) become worse than The Pale in the 60s and 70s with sectarian riots and bombings. And I can't see a German government implementing the kind of enlightened Home Rule principles London did.
