I think this is a great Idea. Sorry for being late to the discussion. I think it would be a great time the mould the lore to fit AOS. I just love the aesthetic of the charge of knights with flowing banners. I thing the idea of Vows and oaths being a way of gain power from your leaders would be a run dynamic for the army. I like the idea of a powerful lord/wizard granting his troops a portion of his power and regaining it as his men die. Your hero starting the game comparatively week but becoming more powerful as the game goes on. It would give your opponent an interesting tactical problem.