OK, so it has suddenly occured to me that I never really asked what size the tree saddle was on my saddle that my trainer gave me. I just assumed it was a medium tree, and went on because she said it fit him great shprtly after saying he needed about a medium tree. He is 15.3 hh and uses a 48" girth. Looking at these photos, what size tree do you think this is? Is it small? Or Medium?