changing out fenders

I have 2 thorowgood saddles which fit both of my horses, but 1 of my horses prefers my Abetta. My problem is that the fenders are too long and when I add holes and shorten them, they restrict my leg movement. (old English rider) and kill my hips. I know that some people have changed their fenders for English stirrup leathers. I was wondering if the change was due to a problem similar to mine or if they had another reason. I would also like to keep my endurance stirrups, but the leathers that I have found are very narrow and the stirrups would slide back and forth. Would that pose a problem. Enough of an old ladies rambling. Any insight would be of great help