If they are rolling then they are not balanced, and wraping isn't the only way to shorten them. Remember the place to put the sling isn't nearly as important as where the hook is placed, you can wrap the slings to make a major adjustment to the length of the sling and move the sling closer or further away from the hook to make a minor adjustment.
The easiest way to make sure the pick won't move after the cut is to place the hook over the Center of Gravity of the pick, sling it whatever way you have to, have the operator pretension the line, then grab the slings and feel the tension by shaking them, you can tell if one is looser than the rest, have him give you a little slack and side that sling a little farther away from the hook. Pretension, check again, then move down to the cut.
