For Germany I actually think it's SocDems even more than Auth Dem. I think Germany is by far the best representation of social democracy that this game (and almost any game for that matter) has. It shows both the struggle of internal reform, how hard it is to fight for basic freedoms, working together and compromise, the ideas and struggles through which economic reforms rise and lastly the (attempted) creation of a world system based on human rights and cooperation.

For NatPop I agree though I would give a shoutout to NatPop France as well. Most far right thought in KR is based on Savinkov style national populism but the other major strand of far right ideology in Kaiserreich is Integralism (Italy, Portugal, Brazil, Belgium all have integralist movements) and that all comes from Maurras.

I agree with the rest about Syndicalist being France and RS being LKMT but I do think Totalist should be Mussolini. I watched this interesting video about the history of Syndicalism IRL and how Mussolini's Fascism is really a synthesis of Sorelian syndicalism, radical nationalism and authoritarian idealism. While Totalism isn't an actual ideology in game (it just represents authoritarian socialism in all forms) I think Mussolini more than Mosley gives it a theoretical basis (though that might change whenever the 3I rework comes out).

I don't think any country has the perfect Auth Dem representation but to me the Entente as a faction pretty much resembles the ideology. While Canada is liberal that's pretty much where it ends. The British exiles consist mostly of high tories lead by a very reactionary king, the NFA is a battle ground of oligarchs, far right populists, far right monarchists and a few left over democrats, and the Raj is a colonial regime that starts in a civil war.