I vote ideology, religion model can transfer well to this, and it would give the game effect we want ie civs with same ideology work well together, using traditional religions on the moon is anachronistic as agencies and corps dont have official religions, plus in the modern era the only religion that actually makes war on other religions isnt likely to build a colony on the moon (no offense here but it seems some religious fanatics are too busy burning and smashing things attempt something as complex as creating a permanent foothold on the moon)
so I like the ideology idea, i also like the idea that you can create a unit that will do the opposite missionary, eg stamp out unwated ideologies, you can call them something different for each ideology or just call it something generic like, re-education instructor or something haha thats a little sinister.
anyways going to do some terraining