You miss my point here. Red hawk was nerfed due to being underwater, that’s why I said withstanding it underwater isn’t impressive. Luffy was weakened due to the sea already and it’s a fire based attack so of course it was weaker than it normally should have been. Base Luffy bodied white haired hordy hard on land without using hardening (to my memory). Also it doesn’t make sense for Zoro to be able to clad his weapons in haki but not his body, he definitely is capable of that. Zoro’s normal physical strength is just way above white haired hordy. To give you an idea of how much oda had to nerf Luffy just to make hordy look decent, consider the following
Hordy gets a massive speed and mobility boost being underwater
Luffy is already weakened by water naturally, his attacks won’t hit as hard underwater anyways and Luffy’s movement was heavily restricted for most of that fight. Even with that heavy nerf and hordy being buffed on roids and being underwater, Luffy never even went all out against the dude. Hordy is trash, Zoro without swords and definitely beat him on land even if Zoro’s physical strength doesn’t match Luffy’s.