That's all just administrivia. Anyone can do this, regardless of class.
Maybe not preaching. Or at least not as effective preaching as a priest. But there should be something that we could give them that would make the P/H combo some kind of warrior-of-the-faith kid of thing in a way that is more than simply RPing your character that way.
Sorry, I took you meant the warrior class when you mentioned warrior.
What if P/H could fight personally, e.g. in duels? Or can they already? In that case, I think it would keep the balance of having priests unable to have a unit, but still keeping a "warrior" feel to them.