why the hell is Kaido cooperating and helping Orochi anyway?
To kaido it doesn't matter what wano citizens think but how outside world sees wano.
Orochi is a perfect face to hide his act of building smiles and an army of zoans. If he puts king then to outside world it would be like taking over wano and giving world government reason to interfere.
But with orochi as Shogun he can not Only continue to extract all resources and build army but he can also put World gov at bay because wg can't simply take over such huge country under a legit rule of his Shogun as it will portray them in bad light to outside world.
Also, they still fear that wano samruais are under orochi.... whatever info they have is because of Drake