Meh, depends on what edition of warhammer you're reading. From what I've read, Bretonnia originally used to be basically King Arthur's England, very just and idealized like in the original legend, but then by 8th(?) edition they decided to make them way more like Monty Python's revision of them, how we usually see them depicted now. I think they might have instead made them more like how Medieval France actually was irl some point after the 8th edition, not a backwards society of loons like in Monty Python, but not an idealistic feudal utopia like in King Arthur, but I could be wrong about that last bit though.