Here's my take on a preacher after getting stuck mid ways.
My back story for him is that he along with several thousand other guardsmen were ordained by an ecclesiastic decree to defend an imperial saints shrine. As the only people allowed within the walls of the shrine were ordained monks or priests.
Of course for most after the battle the holy voues taken were forgotten but for some they were affected by the experience and have since grown as a small warrior brotherhood.
Still some thinkin to do on this so will update tomorrow.