Even Zoro has a robust shot at breaking Queen's sword if he coats his body and the sword is not coated. I bet his haki is likely much harder and tougher than that material. π€ technically even if Queen coated his haki should be superior but better not exaggerate out of precaution. Queen can damage Zoro if he doesn't cover himself with barrier haki but perhaps it would take heavy hitters such as Brachio Bomber or the grip also based on physical might.