I see, as expected, the insecurity is in the room with us...
If he was capable of beating Kaido in what Kaido is best known for, he is surely beating him in some other stats too.
I repeat, Kaido's main selling point - the toughness is beaten by a mere underling.
In the rest of the stats, Kaido exceeds him by a country mile just like he exceeds him in toughness by a country mile, lol.
Aka he doesn't. Their stats are very, very similar. The only stat that Kaido beats him by a country mile is Destructive Capacity because King doesn't have a single move that can destroy an island of Onigashima's size like Kaido can with his Blazing Bagua.
Note that I didn't say King can't destroy island of Onigashima size because he can, it is just that he cannot pull it off with one move.
He would just have to spam several Tempura Udons and would achieve the same.
Should I tell you that King beats Kaido in speed by a country mile or can you figure that out by yourself?
Should I tell you that King beats Kaido in lethality too? Not by a country mile but he is ahead regardless.
Lunarian flames > Kaido's flames. Swords > Clubs. And no, the aCoC will not turn the tables of heavily inferior damage type.
That brings us to Shiryu beating Blackbeard in what Blackbeard is supposedly best at - the supreme DF merchant.