Maria is a spectacular game, but I think y'all are crazy. Maria, with its special rules and exceptions, is definitely more complicated than Julius Caesar. It's got politics, election cities, Saxon neutrality, Hussars, etc.
I played Friedrich 10-15 times before playing Maria, but I still struggled with Maria's rules a bit. I don't remember why, but I did.
If someone wants to learn Maria, and is relatively new to wargaming and/or "complex" games, I always push them to play Friedrich first - just because it's more straightforward. And Friedrich is still a great time, even if it isn't quite at the level of Maria.