I place my bets on Sengoku. Even Roger said that if the marines really wanted him dead, they would have to send Garp or Sengoku. So if Roger said that, I think Sengoku claps this fight.

Hard question, because Sengoku didn't show all of his strength.

True though, wish we saw more of him when he was younger.

Sengoku at Marineford isn't enough strength to beat Kaido, and Sengoku Marineford is the only time Sengoku Strength showed, so I choose Kaido.

Prime Sengoku high diff. Ik he can scale to prime Roger but he seems way too bulky and would have a hard time hitting Kaido

Likely Kaido Extreme diff

Prime Sengoku Extreme diff

Kaido high-extreme diff

Sengoku High Diff