I am trying to change my faction midgame once I get too strong. For instance, I want to play as Rum, take over most of Byzantium and switch to Byzantium to get it back. Problem is I don't know if difficulty is retained. I started as Rum with very hard, but when I use hotseat the difficulty changes to normal. How do I retain the difficulty? Or is there any other way to easily switch factions?

Thanks.