Huh! Sanji fans would be fine with it?!! They were putting Sanji up against King till Marco showed up.
If Who's Who is equal or near equal to King/Queen/Jack, then it won't be an issue. Who's Who will be in worshipped to high heavens by us (Zoro fans) and denigrated by rest. If Who's Who is decidedly weaker than King/Queen/Jack, then we would be salty. Similar is true for Sanji fans.
Currently, the consensus in Zoro fandom is that Who's Who is decidedly weaker than King/Queen/Jack, hence they refuse to acknowledge Who's Who vs. Zoro as the main Zoro fight.
But I got the feeling that Oda will never show Who's Who's power-level in relation to the Calamities. So, if Zoro vs. Who's Who end up being the main Zoro fight for the arc, there will be blood spilt between Zoro and Anti-Zoro faction.
Guess what?! Same is true for Sanji and Anti-Sanji faction. Only three factions will end up as winners if Who's Who end up being Zoro's main fight:
- Luffy faction
- Kid faction
- Law faction
But...all things considered, Zoro vs. Who's Who being Zoro's main fight is a strong possibility right now, even if rest of the Zoro fandom doesn't agree. Fortunately, up to Ch. 981, Zoro remains a main player along with Luffy and Kid. So, this is probably not the time for Anti-Zoro faction to be excited.