He believes in a "world government" that explicitly has the founding mythology of the 20 kings being Gods who created the world, which is what Aramaki said. The only difference is that Akainu(possibly) has some sort of private dislike for the modern day world nobles, but he sure as hell doesn't mind maintaining the system that keeps them at the top.
Again, the distinctions you're making are just arbitrary. As Zoro said, COC is for people who are either captains or captain like.