My halter bred paint gelding (own son of RH Mr Imprint) measured between an XW and XXW for the County Innovation and I ended up getting him a custom XW hoop tree Black Country Ricochet... Apparently halter horses weren't meant to jump
Appendix Quarter Horse, maybe 16hh. She got the worst of both worlds. Withers AND a broad back, lol. So far the best fitting saddle (not perfect, but almost!) is a County Stabilizer, wide tree, with Skid Row panels. Now THAT was a hard one to find!
"On the back of a horse I felt whole, complete, connected to that vital place in the center of me...and the chaos within me found balance."