If I recall, that's the style with the center seam that goes between the first and second toe on most feet? Some patterns bring the seam up top with a pointier toe. The heavy leathers work ok on them if you keep that seam very flat. If not, it can bite. I've used a baseball style stitch that worked well, or a very fine seam with a welt worked ok also and might have lasted longer as the threads were protected more. Due to the basic shape of this style, the foot itself acts as the last and has to make it's shape with the leather. I draft a pattern for each foot and it eliminates much of this, but not all of it. That's the downfall of this pattern especially in a heavy leather. This is basically true of any center seam or pucker toe style in my experience. The heavier the leather, the more difficult the break in period. Wet them, wear them dry is best.
In my shop, the cost difference in leathers is negligible for moccasins. Labor on the hand sewn mocs is obviously more than anything I can machine sew and get away with. The seams that don't show can all be machine stitched for all but the most purist and no one would know any difference by looking. Saves some $$. I'm just practical that way when spending someone else's cash.