Its always baffled me why Bethesda thinks its a good idea to make horses that want to fight everyone. Often times I dismount from my horse a decent distance away from an encampment where I engage some hostile NPCs only to have to avoid my own horse moments later. I have hit my own horse a few times and he's turned against me before. Kind of annoying. There should be some kind of command you can give to your horse to stay put or avoid fights.

Then sometimes the opposite is true. He'll run off and I can't find him after the battle.

I don't know, I quite like Horse vs Dragon. Plus it would be kinda lame if they just stood and got killed.

Elder Scrolls horses just wanna fight everything! Even if the battle can't be won, like a war between men and maggots. Or Dragons and wolves. Or men riding dragons throwing wolves at maggots.

That's how I lost Shadowmere, she just darted off into the wilderness after some creature and I never found her again...