Zoro has always been Luffy's right hand man. But not every right hand man is a first mate. You fail to see my point because you haven't understood yet that "first mate" is a specific title in this manga that hasn't been given to every right hand man. So before answering me again I'd suggest you to investigate the canon information I'm sharing here because you're completely missing the point.
I guess you believe that an hippopotamus is an equine that lives in rivers, since you like to take words literally.
I covered this mistake recently so I will just quote myself:
The actual meaning of that word, to summarize, is way different than your literal yet flawed understanding of it.
First mate is first mate. Benn Beckman is Shanks's right hand man and his first mate as an official role while Lucky Roo is their combatant. Marco was Whitebeard's right hand man but the doctor as an official role. Zoro is Luffy's right hand man but the combatant as an official role. And none of these two are officially addresed as first mates in their vivre cards.
I guess you believe that an hippopotamus is an equine that lives in rivers, since you like to take words literally.
I covered this mistake recently so I will just quote myself:
The actual meaning of that word, to summarize, is way different than your literal yet flawed understanding of it.
First mate is first mate. Benn Beckman is Shanks's right hand man and his first mate as an official role while Lucky Roo is their combatant. Marco was Whitebeard's right hand man but the doctor as an official role. Zoro is Luffy's right hand man but the combatant as an official role. And none of these two are officially addresed as first mates in their vivre cards.