You are generally right and that is why there is the controversy of whether Mormons are really Christians since they reject the Creeds. From a historical and theological point one can say Non-Nicene Christians.
Mormons are not Christians. Polythiests can’t be Christians.
What controversy? They're not Christians, pure and simple. Sure, they might borrow the lexicon of Christianity, but they infuse it with all-new definitions and backstory.