Hi Buckaroo,
since you haven`t gotten any response so far I thought I do so. Hope you do not mind that it is me again...
Last year I had a chance to visit both Dry Fork Saddle Shop =MCCall Saddlery and their saddle tree manufacturing business Timberline Saddle Tree Company. I sat in a lot of different model McCall saddles and remember very well that the wades I sat in all had their low spot in the seat near the cantle while the swell fork saddles I sat in had their low spot more in the middle of the seat - much better ! But all the groundseats got built by the same person. So if you were to contact I bet they could but in a different seat in the wade if one would want it.
How they fit a horse will of course depend on the fit between bars and back. I seem to remember that what McCall Saddlery calls a modified QH tree is what Timberline would call a Semi QH tree and if memory serves me well then it is build at a 90° bar angle and 6 1/4 "gullet width while their QH tree is on 92° bar angle and 6 1/2 gullet width.
I had found the people at both companies very friendly and they answered the ton of questions I came up with. Both companies probably can explain the difference between the wade styles.
Hope this helps.
Tosch.