It's no surprise Shanks's offense shits on the likes of Big Mom or even Kaido for that matter. Shanks is an offense-centric fighter while Kaido and Big Mom are more defensive types. Shanks's offense is much better than the Rocks duo just like how their defensive prowess like endurance, durability, etc, shits on that of Shanks. With that being said, it's obvious Shanks is stronger than Big Mom, but this chapter isn't enough to put him over Kaido, period. Kaido's still number 1.