What BS.
What proof do you have that Kaido will be or more importantly stay unconscious. Oda has showed us time and time again beast pirates, with true df, have impressive endurance and recovery powers. Kaido has the best so far and he hasn't even used his awakening which will increase his strength and recovery powers.
Luffy might put down Kaido but keeping him down will be the challenge. Not even the marines could permanently out him down. That's where the problem starts. Luffy isn't punching Kaido several times and then Kaido staying down. He will continue to get back up and return to face. Luffy doesn't have infinite haki but Zoro could put him down permanently if he grows stronger during Wano.
Kaido wants death from a monstrous samurai. He doesn't know Zoro will be that samurai or swordsman because he doesn't know Zoro's ambition.