No one said Zoro gets disqualified from being WSS if he can fight without swords...
I said: people can still fight after dropping their swords, then mihawk's title would mean nothing for them. Can you read?
WSS = About being swordsman.
You can be a stronger swordsman, and can lose to a weaker swordsman due to other things like physical stats and Haki. Because everyone has that, Luffy, Sanji etc. they are not swordsman. See the Pica fight, Pica used sword, then he drop sword, if Pica's Haki was stronger he would beat Zoro.