Shintoismn, Hinduism, both have a very strong pantheon like polytheistic tradition, and both are core religions in Civ 5.
As I said, Pantheon actually means "set of gods in a religion" but this is obviously not how it's meant in VP; rather it is a sort of precursor to a real religion. I also specifically mentioned polytheistic religions not being a Pantheon in the Civ 5 VP sense earlier, for the same reason, after you said that a Monastery could be linked to just one god, like a god of hunting; you're flip flopping all over the place with your position now.
That's a subjective view. A monastery is a housing for follower of a religion, which dedicate their life to the gods. A place where they pray, work and life. I don't see any reason why a pantheon priest shouldn't life in a monastery.
Yes, I know it's subjective, that's why I said "for me"; I still find it weird that there would be a Monastery full of monks praying and philosophizing all day while worshiping a god of hunting; that's not how Monasteries work, in my opinion; there needs to be a much deeper, richer, actual religion involved.
Also, what's with Buddismn? There's no God in the Buddismn religion, only a prophet.
It's still a religion that concerns itself with all aspects of life and life itself; it's not just some pantheon about a god of hunting.
As far as I know Gazebo gave pantheons also a small pressure value. Missionaries were exsistant all time, even in pantheons. They were simply not called that and they didn't dedicated their whole life to spread the religion. This is more an invention of later ages.
A philosopher or someone who takes "thinking and talking about spiritual matters" up as a hobby is not a Missionary. The Missionaries you buy ingame don't go back to work your fields after they spread their religion, do they?
And more on point: I find the way Pantheon is set up in VP to be fairly realistic, actually. If we take a look at the early Mesopotamian peoples in the Mesolithic, you'll see that there were many different gods being worshiped by different tribes, which are more like VP Pantheons viz. being about a specific aspect of life, and eventually a lot of those merged together (both the tribes and the gods) and formed a more fully fledged, enriched religious substructure, which is likely the basis for religions like Christianity, for example, so I think going from that kind of simplistic, more explicit religious precursor to a more developed, more abstract religion is a good model for human history.