The following video came across my feed and hit something I've been talking about for years.
Set aside the conclusion. Focus on Tabletop applicability, both in terms of worldbuilding and in rules/content design. We, like the video presenter, shall take the perspective of an engineer here.
Remember Runequest? What's its big deal? That religion, in its full complexity, is made playable in a manner that players can comprehend in a manner analogus to the way that non-Christian religion actually works. Call of Cthulhu does something similar with how it presents Lovecraft's nihilistic cosmos via its rules.
This video explains how and why the human practice of religion works as it does, and it is far more applicable to non-Christian practice (something that is how things are in most Fantastic Adventure gaming play, at least in theory) than to Christianity due to specific elements of Christianity that make it the outlier in religions.
It also, without even addressing the hobby, shows why the Cleric (a) is not a generic priest and (b) why implicit cosmologies hard-coded into a game limit the scope of practical religion capable of being modelled in a game. There's a reason for why you can't have a proper representation of Christianity in Legend of the Five Rings/Legend of the Burning Sands: the rules regarding how the supernatural and sacred work get shattered by implementing Christianity into its setting.
The obvious conclusion is that this justifies other priest classes.
The obvious follow-on is that games will get the priest classes that the rules support via their mechanics and procedures.
The catch is that people will do this poorly and get shit results that don't deliver on the expectations; to do that you have to know the game you're designing for, which means you need to read the fucking manuals and then draw out the second and third-order effects of their rules and procedures. With that mastery in hand, your design will leverage those structural elements and emergent effects to fulfill the expectations that users will have.
There's a reason that I've made a draft adaptation of Palladium's Warlock O.C.C. to AD&D1e; it is to illustrate this very thing, because AD&D1e can support the concept, but those who don't read and study the game's manuals will fail to achieve the desired result. Shaman adaptations are likewise not just a variant Cleric.
The same applies to other games. Your priests need to reflect the mythos and cosmology that comprises their religious practices, and that needs to be coded into the rules so it is part of the experience of play.




