Yeah Narratively Akainu is apart of his men/former men :
- his rank
- only guy who beat an other top tier
- fight WB
- killed Ace the MC bro
- give Luffy a permanent scar
Obviously that set him apart of the others
And after fighting Whitebeard, killing Ace, giving Luffy a permanent scar... what did Oda do?
He wrote Akainu & Aokiji's fight, as if they were near equals in strength.
It shows that Oda went all in with Akainu on Marineford, because that was his arc to shine in (Aokiji had Water 7/Enies Lobby & Kizaru had Sabaody).
That doesn't mean that Akainu was on a completely different tier from Aokiji & Kizaru.
And why are we pretending as if the relationship between FA Akainu & his Admirals are like Pirate Captains & their Subordinates?
Can you even imagine King or Katakuri talking to their captains the way Fujitora talked to Akainu at the end of Dressrosa?