Because in humankind, even when I theoretically choose a monotheistic historical religion, in practice I have to always remain the whole game with the precept of shamanism or polytheism? Which brings me to another question, why can these two permanent options be something that is not unique to your religion and other options suffer from such a limitation?  I don't understand , for example, as “Be Not False Witness" as something unique to a single religion, with the Ten Commandments being shared principles among Abrahamic religions.
As it is, I prefer to play with the religion mechanics disabled or some MOD that includes true monotheism in the game. Is this possible?

Grateful for the attention.