Alright, so let me clear a few other things up.
When (for example) the nords take a city or castle, say from the Swadians, the villages connected to them produce Nords (after 72 game hours!) for both you and the AI (only if you replace both update_volunteer_troops_in_village -1 and update_npc_volunteer_troops_in_village -1) So no more mixed armies for the AI! You can still recruit other factions units from their territories.
Let me think if there is anything else...
the Magelords original tweak for this doesn't work because there is a line that needs to be changed (I don't feel like going over that) because it doesn't take in account for the new faction so when you make your own you can't recruit men from your own.
Those tweaks I posted are only for War Band.
You really should make a mini-mod for each.