That is your headcanon, cuz Kaido in a previous confrontation with a monster like Oden used a full army against 11 people to just win.
So spare me this bullshit cuz is pure bullshit
. Kaido even stated that Oden could have won easily if he had call all samurai to crash the beast pirate. He used all tricks possible to weak the samurai force so that at the end only Oden with 10 guys faced the full force of the beast pirate.