Zoro needs to find out more King's tricky ability, it's probably related to his race.
There must be something he can do to break his defensive capabilities
Oda treats these 1st Commander fights similarly.
Luffy needed to find out a way to counter Katakuri's CoO, so he could have a chance, that was the hardest part of the fight.
Zoro using Ashura next chapter seems a waste, it's too early