—No offense intended in my reply—
Are you accustomed to mounting from the ground?? I have seen a fair number of people attempting to mount from the ground who manage to pull the saddle sideways as they struggle to get on…
Mounting from the ground should be a quick and somewhat nimble spring from the ground. If you have to hang, and pull and drag yourself on even a saddle that fits will probably slip. You shouldn’t have it over tightened so you can get on.
He doesn’t appear to be “overly wide” from what I can see, just an average Quarter “type” horse.
Very nice boy…