Concerning the Enhancer Beliefs, I want to talk about the Syncretism Belief.
Syncretism:
+1

,

and

in the Holy City for every 2 :c5population: of other Religions in owned Cities.
+1

in a City for every 15

per turn it produces, capping at half the number of Followers.
The second part is quite simple, if you have a science orientated civ, you get more faith for something you already try to get as much as possible. It is quite straight forward.
The first part on the other hand is just from its reading very powerfull, because scaling with just 2 Followers of a other Religion for +1 of three different yields is awesome and especially, there is no cap to it!
But I have to say that I nearly hardly ever picked that belief, because it is like Pagodas, you need other religions in your city to make those beliefs work the best, which is mostly dependent on your neighbours and their possible religions.
On the other side, having to many other religions in your empire will cause religious unhappiness which I try to generally to avoid.
So I rarely pick that belief, how do you see it?
But that wouldnt be enough to justify my post, because with that belief there is an elephant standing in the room. In one of my last games I conquered as Rome the Celts' Capital and let the Holy City untouched, because they snuck up Hero Worship which I wanted to get originally for myself.
As I went on conquering, I sadly had to learn, that the Holy City doesnt trigger the Founders Belief effect, so I was nearly inclined to remove the Celts' religion entirely, because I couldnt use the Pantheon of it either. But when I went through my city list looking for cities which could build Wonders beside my Capital, I noticed, that the Celts' Holy City was on top of my production.
Not only that, it was the same for science and faith. It was all thanks to Syncretism. As my empire grew, that bonus got absurd. With around 20 cities at roughly 20 citizen per each, that bonus got +200! For three yields, from just one mechanic!
So I have to say, that belief is up to be broken, if you are lucky that one of your neighbours enhanced his religion with it, get his holy city and just keep that religion there, the rest of your empire can have your own or another religion. That boni will just sky rock!
So I would say, there should maybe a limit to it like for some of the founder beliefs. +200++ production before any percentage modifier is just too strong and like it worked for me, I dont think that was the intended way how it should be used.
