The thing is, they could have given them more identity.
It's the flaw in the fighter subclasses: their identity was based solely on mechanics rather than story or narrative. So the subclass tells you nothing and means nothing in the world. Outside of combat, in the other 2/3rds of the game, the subclasses mean nothing.
And it makes it hard to design more subclasses, as the two main designs have been filled. You can't have a gladiator or knight subclass now, because the complexity is tied to subclasses. If a player wants to play a newly released bounty hunter or phalanx or dreadnought subclass, either it has the complexity they want or their narrative concept doesn't fit the design. The subclass might not do what they want to do.
A better idea would have been two decision points (like the warlock that picks patron and pact boon), so the fighter has one choice that determines their complexity and another tried to their subclass & story. An option at second level that gave all fighters the choice of having maneuvers (complexity) or static bonuses, followed by the standard subclasses that are pure flavour, and also give the class more of that exploration and social support the class needs.
That way you could have a knight fighter that does knightly things without having to decide if it is complex but alienates players who just want to hit stuff but also want to play Lancelot, or vise versa and it's simple but bores players who want choices each combat.
But too late now...
