Personally I believe that it builds calouse and character. Take that bow out and shoot a dozen arrows without a guard or tab/glove.
If you decide to shoot more, put on the protection. I do it all the time.
If that sucker is slapping your arm and leaving bruises then we have a problem.
And a leather brace doesn't cure the problem,
only makes you comfortable
You either need to change brace height or form.
I guarantee you will figure it out.