You could call that bad writing but to be fair Blue Scarf doesn't have to agree with everything the Gorosei wants
He's just doing his job
He'd rather let Luffy/Kaido kill each other but the Gorosei wouldn't, they want to protect their boy Kaido from Luffy
He's just doing his job
He'd rather let Luffy/Kaido kill each other but the Gorosei wouldn't, they want to protect their boy Kaido from Luffy