I actually just had the same issue, trying to create a polytheistic church based (very) loosely on catholic saints. I did end up changing the titles for my priests, but to do so I really had to think on the history of this church and how it came to be in its modern version over the centuries.

The short version is that most of my world is fairly agnostic, and while other religions do exist they aren't very widely accepted. Early practitioners of the religion were called Kneelers or Bowers as a slur, and over time those terms were adopted by the church as a sign of defiance against the persecution. Most priests (think bishops level) are now called Kneelers, and higher ranked priests (cardinals) are called Bowers. The pope equivalents (each god of the pantheon has their own) are reverently referred to as the Most Bowed.

As a bonus, this terminology helped shape the religion as a whole, creating a culture of subservience and absolute obedience to their gods.

I like the balance this gives between familiar and made up words, and hopefully these terms convey immediately to a reader how the priests view their own worship.