As shown by panels Zoro's real dream is to make Luffy Pirate King instead of becoming the world's greatest swordsman. There is nothing wrong with that. That is what Ace wanted to do with Whitebeard. It just feels vain to have zoro say that he will become the world's greatest swordsman. I wish a man devouted to his sword would manage to do that. Zoro is such an underwhelming swordsman that it feels kind of out of place to have Zoro become the World's Greatest Swordsman.
I wish there was a greatest vice captain title :'(