User blog comment:HanataSanchou/Expect The Unexpected/@comment-3185063-20160402134256

I have the suspicion that all three of the alliance were either forced under Kaido, or they pledged alliance either for their own means (Concerning Shanks) or out of fear of Kaido's sheer power.

Either way, Kaido essentially has five of the Supernovas under him, while the rest are allied together against Yonko (Luffy, Zoro, Law), are under Big Mom (Bege), or have no apparent affiliation as of yet (Urouge, Bonney).