He wasn't saying it had to be Bishops and the like. For example, the SA equivalent would be Light or Luminary.
And the CoH would use High Clerics and Revered Clerics with our ranking system. But you know what? I'd take the Prince-Archbishop/Prince-Bishop as a feudal title if that's all the game presented and just chalk it up to being the titles used by non-Faithful. In the Church, I'd encourage people to use OUR titles and forms of address.