I am sure this is true, but I have never tried key binding in all the years of playing. Trying to remember which key worked for what would just leave me staring at my cheat sheet while the fight went on. Besides, I would have to look at the keyboard every time to find where the key is. I can't type worth a darn so the keys are not instinctive. And if I change the standard strafe keys qweasd to something else, then the rest of my games are hosed.
But several posters make a great comment. Why is the longbow knock back skill 4 and the short bow one is skill 3. Now I have to wait for the skill to recharge when I really need it because I used it already. If the order of the skills were similar, I wouldn't care if I cannot move them.