That isn't possible even on normal. I play on normal and they still do a lot of damage. Sure they might kill you instantly on hardcore mode but instead they do a lot of damage. I tried to fight face to face against 4 deathclaws, i died pretty fast because they all hit me at once. And if you're going to melee one you'ill have to use a lot of stimpaks. They have high damage resistance. Legendary deathclaws, impossible to melee. It killed my 26 character in one hit.