Well, everyone can defeat anyone, it's just whether how probable it is.
Zoro would last longer than most opponents against Luffy because of his amazing stamina and tenacity. As for swords being Luffy's weakness, swords are everyone's weakness. Getting cut is getting cut.
There was put some diatance between Zoro and Luffy during the Enies Lobby arc imo, and Zoro has caught up to almost the previous gap between them. But Zoro has stated himself that he won't follow a weaker captain, and he's not the guy who jokes around.
I'm saying Luffy wins. What difficulty he will beat him in, I can't really say, I don't know.
I think that Luffy will put some distance between them again, if he fights Doflamingo. But I think once they reach Wano Country, that it will be like Zoro's arc, where he will fight someone reeeaally strong, and defeat him, ending up like how Luffy was after his fight with Lucci. So Zoro will probably close in on the gap even further then.
Hope you enjoyed my post
