Don't get me wrong, Akainu is in my eyes a formidable angonist because he is a moron, he has a black and white vision of justice but ultimately he just follows orders because that's how he was raised and trained imo.
Somehow he is the perfect opposite of Luffy who represents freedom of choice, Garp his only family wanted him to become a marine and to bend to their rules, yet he chose the opposite side by becoming a pirate. Akainu chose to follow blindly the rules and by doing so, rejected any kind of freedom, he can't break free even though his opinion doesn't match those of his superiors.
He is a follower, his willpower is weak as fuck, he will never be above someone like Kaido or Luffy for example because they demonstrated the strongest will so far