Hi Tumai. :)
Do you mean you would leave the other chestnut without anything below her dock?
It sounds a good idea in theory, but the only thing that would concern me, is horses rely on their tails to swoosh/flick flies away etc
Could you not just pinch a portion of it, just to bulk fidgets up a bit, so it doesn't look quite so bad? Then that way your other horse would still have her tail to do the neccessary.