Do people realize Luffy is fighting 2 Flying Six at the same time?
People who are above of Hawkins? The same Hawkins that overpowered Zoro?
Of course he would need Gear 4.
Which is why I called it bad writing if Zoro is going to solo fight King, and if Luffy is going to solo fight Kaido. They should team up against them, they are still not close to Yonko executives and Yonko.
Yamato, Law, Kid, Jinbe, marco, Neko, Inu, all the samurais, infact all of the WB pirates survivers need to help them in this fight.