Except Oden got oneshot by Kaido.
And yet Kaido was gonna die nonetheless without interference
It's funny how people forget how swordsmen work. Swordsmen's primary defence is blocking with swords. That's what oden used to block an attack from Roger himself. His swords.
If Oden wasn't distracted first of all he'd cut Kaido while he was knocked down. Second he's block Kaido with his swords.
Because that's how swordsmen fight.
And in the end, Oden would win