I don't have an answer for you but I just wanted to share a bit of trivia with you. I read or saw something about how a horses mane falls determines which brained it is.
If its on the left side its left brained on the right right brained. I'm not sure how true it is but figured I'd throw it out there.
Maybe your horse is using both sides of its brain which is a good thing. If you try to make it all go one way, you may be dumbing him down