I can only say, when I watched the first clips, it just looks like your motion is out of sync with your horse's motion. The latter clips does "look better", but blocks don't line up. (head-shoulders-hip-knee-foot) The angle of your hips should only close as much as your horse's angle opens as he jumps if that makes any sense. Another way of putting it is, if you pick a fixed object off in the distance beyond the fence you're jumping, whether you're cantering to the fence or jumping it, your relative position should stay the same in the sense that the distant object doesn't move up or down. Does that make any sense? If you jump some gymnastic grids, it would give you a really good feel of how the horse moves beneath you with each jump since they come in such rapid succession. It would get you more into the habit of absorbing the jumping motion with your lower legs and knees and letting the horse come up to you rather than trying to jump for him.