You are so right SmoothTrails. I have a RMH mare. No matter where I sit the saddle on her her shoulders she will always move it back to a certain spot. Doesn't matter what type saddle. I tried narrow gullet, wide gullet, regular tree, wide tree, gaited tree, you name it I tried it. I finally ended up with a regular tree saddle. She just has so much shoulder movement that the saddle must sit back right behind and above the shoulder.Just be sure you do not have the saddle sitting on the points of their shoulders as they will not be able to gait correctly. You should be able to slide your hands to the point of the shoulder and be sure that they have at least an inch of room between the tree and shoulder. It varies by horse so you may have to use some trial and error on where exactly to place the saddle.
Good Luck![]()