Allow us to add custom civs without workarounds if you’re not going to add new civs with DLCs. Right now, you can’t really add civs, the UI is not made for custom civs and you can’t add civs from several mods at the same time as far as I know like in the Civilization franchise.
Alternativelly add new civs via DLCs if you don’t want us to give the possibility. Or do both at the same time