A lot of these issues have been touched on in other posts, but the community seems mostly agreed on them. Archers are way too powerful. Autocalc (and thus the majority of battles taking place) favor horse factions too heavily. Unit rosters still need work. More factions are needed or the current ones need more impact.
To keep with the OP, I've tried playing as Sturgia and it was really hard for me. The interesting mechanic with their faction is you can have lots of good infantry and naturally acquire good cavalry while levelling them up. The other good thing about their cavalry is they are also decent on foot so you're not really handicapped when it comes to sieges. Not a long list of pros, but it's something