Wagtail
Horse servant
I didn't watch them all the way through as short on time but first one - can't see any issues but he doesn't do anything for me. The second one may be unsound behind. Left hind in particular. He is also straight through the hock and has very low dipping hind fetlocks. I personally would worry about his soundness. The third one keeps going disunited in canter. I would again suspect a soundness issue due to the frequency of this occurring.