Just watched this movie last weekend, and overall the horse action was pretty good. They didn't mount steppe nomads on nice, shiny stabled horses, but let their mounts be a bit scruffy.
Unfortunately, they made a major mistake early on that had me and my husband groaning and facepalming.
A group of characters were being chased through canyon territory by "nomads." (We don't get to see why). They have the horses they're riding and four pack horses.
One of them decides it's a bright idea to cut the pack horses free. With no prompting, chasing, yelling or anything, the pack horses go down a different canyon, leading the pursuers astray.
This would never happen.
A horse that's loose will do one of two things:
1. Follow their buddies.
2. Try to go back to their own territory.
As these horses were at least supposed to be a good way from home, they would have followed their buddies. Period. To get them to go down a different canyon would have required yelling and probably a smack or three with a hand or even a whip. Something.
Remember: Basic horse psychology is that horses feel more secure in a group. They don't go away from the herd without a reason.