That doesn't matter, because the Lunarian DNA is stopping the brunt of the attack. The Wapol Metal is much more effective in reducing injury in the event the attack makes it through the skin, then if it wasn't there at all. Once you make it last the skin, nothing prevents the cut from going all the way.
It's like cutting through a metal tube with cotton in the middle, and cutting through a metal tube with stone in the middle. The cotton will do nothing to prevent the cut from being deeper, the stone will, even though the metal stopped the bulk of the momentum.