When the majority of peasants in a region are pagans, there is no majority belief.
"Paganism" in BM is not a single religion: it simply means the hodgepodge of local superstitions and beliefs that exist outside of organized religions.
Yes, I know. The point is the current system encourages pagan Lords to simply forbid all preaching and temple building, and this gives them all the same advantages as joining a religion and working on preaching their region to majority belief would. It's a minor point, but it is a factor.
Since there is no majority belief, wouldn't it make sense to say that a majority of the people have a faith different than that of the Lord, whatever it is?
Then aligning the Lords and the peasant's faith would be a bonus, rather than misalignment being a malus that can be negated by not having religions at all.
