Some very strong and intelligent creatures have an impact both on the diplomatic and on the army level. How are you handling this? Are dragons and similar beings characters and also unit types? I'm thinking of cases where for example a balor takes over a human county and then only threatens his neighbors with the small human army of his new holding. Even with additional devil event troops, shouldn't the mighty balor somehow be able to use "himself" as a unit?
You could use events and decisions like they do with dragons in the GoT mod.