They are both teachers. Tsunade has super strength but low durability while Yoruichi is fast and durable. It is not shown yet if Yoruichi has bankai or not but I’m assuming she does. I think she can win this battle without bankai though. Plus Yoruichi used to be a ninja so she still knows hand to hand combat. She also mastered the electric move but I forgot what it’s called. Yoruichi wins.