Why Russians turn into Hungarians? It's really inaccurate historically

Argentina was Spanish, but with a significant amount of german immigrants.

You can find their natives names in the History section if you care.

If your question if why the devs did not use those names for the civs, as they did the 2 others I dont have insider knowledge, but my guess is they dont care, either because they are a bit far culturally and geographically from gaming produced in the US, or they dont have the same relation to their European names as Natives in North America do.

I wouldnt care much tbh. If they want it, why not?