I guess I just need somebody to talk me out of the tree.
It won’t be me.
A tree is supposed to distribute pressure on a wider base, or area.
I feel your pain, though, having two very round, beer-keg-barrelled, mutton withered mares that are really comfortable bareback, but hard to fit a stable saddle to.
Part of the ‘saddle fit’ solution has been to address how the horse braces against the saddle. The horse develops a lean, a one-sidedness, goes with his/her ribs arced one way but not the other, and you get major dry spots, soreness where the saddle goes, and such. It becomes a spiral of self-perpetuated soreness that increases the horse’s habits of using himself wrong, which contributes to saddle soreness, which confirms the horse using himself poorly…
It was not until I could get my mare much more ‘ambidextrous’, using herself better, and thus her back addressing the saddle better, that the saddles I used ‘fit’ her better.
Yes, there are definitely saddles that fit different types of backs. But remember that backs are muscular and flexible, while the saddles are not.
Making a saddle tree flexible like a back, asks for trouble because you can’t distribute pressure effectively if your base is flexible ‘to move with the back’.
The hard part is finding someone who has a true and deep understanding of how a horse should move. There are lots who have a lot of understanding, and know it when they feel it, but they don’t know how to break it down for a ‘difficult horse’ or a ‘bad mover’ so as to improve ANY horse’s movement.
Add that, to the part where if you don’t have someone who is keeping the attitude, cooperation and willing participation of the horse absolutely paramount, you won’t get far…and it’s pretty hard to find someone to help get a horse to ‘fit his saddle’. (Assuming, of course, that it is a reasonable size for the horse. I don’t mean to say that you can take a too narrow, or too wide, saddle to fit a horse it isn’t made to fit.)
When Aktill comes back, he might chime in, he has a better understanding than I do about saddle trees, and so he might explain better.