My gut feeling on the Mongols is that they would stop eventually, for much the same reason they did historically: The big man dies and they have to go back to figure out who the next one will be.
I don’t do much medieval gaming but it’d be a fun exercise in any event no doubt. Remind of me playing Crusader Kings 2 on the computer.
The what-if I might do in the future is a tongue-in-cheek 2nd american civil war. Communist northerners versus Theocratic southerners. Not very serious at all but I don’t know if I’ll ever get around to it.
Nordic Weasel Games