Ultimately no matter what you do, some small percentage of your players will cheat. Every major game on the market has paid cheats which fully bypass the protections available for it. It's better if those cheats can only buy them a little than buy them a lot. It's not worth investing a lot of effort in more than basic cheat protection, it is worth investing it in handling as much as you can server side and exposing as much as you can client side as that is something cheaters can't game.
This sort of behavior becomes impossible. If they have to aim in a fairly human manner, they can still be killed by anyone walking up behind them for example. It may provide some bit of unfair advantage. But not nearly as much as is possible in many games today.