The fenders may be shorter on a 14" which would better suit your height/leg length. That's great if you have enough room in the 14". Don't sit jammed against the cantle, the see if you can fit two fingers between your upper leg and the swell/forks. The fenders on a 15 will be longer. If they need shortening get a saddlemaker to shorten them from the top. I take a tracing of the shape then remove the excess leather. The edge is buffed and dyed to match. Your fender has to be short enough that you can use stirrup hobbles above the stirrups. In deciding if the fender is too long, run the fender and stirrup leathers up as high as possible. They might not want to move so find someone with more grunt than you have.