Champions are too powerful
I got a hold of a few champions early in the game and went exploring with my sovereign. We killed everything in sight, leveled non-stop, kicked a** and took names. Eventually I came across another faction so I declared war and with only the four of us I destroyed them all. I won the game with four champions and no need for even a single unit, nor magic, nor anything except champion equipment. I'm not saying I didn't have fun, I'm just saying that champions maybe shouldn't be that powerful.
My suggestion would be to have most of a champion's ability be to boost the army's (non-champion's) power instead of being an individual powerhouse. I saw some of that with the level up powers you could choose, which made me happy, but since I didn't need an army in the first place the abilities were kind of irrelevant.
I end this post by saying that the game is awesome and if nothing at all changed I would be happy with the game as it is.