What happened?
I don't really like Greenbull but bias aside, he performs better against Yamao / scabbards than Kaido.
Had he actually used the sucking move he used to Queen and Raizo against her (who is already a sitting duck trapped in his roots), that means he can actually negs her, in 1 vs 8 battle.
He was portrayed to be not serious so far, and only will be serious in round 2 (which is interrupted by Shanks).
Means non serious Kaido can perform as much as Kaido did (defeat all scabbards and bonus: Yamao) without receiving as much damage as Kaido.
Hell even in Marineford when Akainu was vs commanders and Crocodile, he only took down Curiel. But here, GB could actually took down all scabbards and Yamao if plot didn't save them.