An old man said "everything is nerfable". Are you exception to the rule?
Well, the NPC is nerfable, but that doesn't mean that he should be nerfed.
also greg, that's not Greg NPC, but HAX NPC, as you are not really resistant to fall damage as you said yourself lol.
It is an NPC Robot, not the real Greg. That NPC would be like a Suicide Booth. Punch him and he will instantly kill you. And he pays you if that kill is your very first Death.