Of course you can be. That's no big issue. But there you use something that's already there in the first place, instead of educating a whole tribe in the matter of "how to be a nice and proper civilization."
But educating my whole population to the Chaos 'words' is not troublesome? Not every German followed Hitler.
Edit:
But if I'm not mistaken, non-reformed pagans(as the chaos religions are) can't reform to feudal/merchant republics. Don't know if this is hardcoded or not, but that's how it works on Vanilla. So maybe, it's not even your guys fault.