The main problem I have with the Fighter design is that while most of the maneuvers are situationally awesome, some are just strong in any situation. These are the meneuvers Fighters will select for their maneuver specialization, and because of the added value of the specialization, the Fighter will likely end up using that maneuver all the time. So while combat maneuvers were added to give martials more versatility and to have their turn be slightly more engaging than just making an attack roll (twice), making Fighters the "best maneuver users" in this way ultimately results in the same thing: Fighters making an attack roll (twice) but with more damage and a saving throw against stunned. If you can add +4 to damage +2 to DC and reduce cost from 3 to 2 to dish out multiple saves vs stunned (arguably the strongest status after Dead, Unconscious, Dominated and Paralyzed) It's hard to even consider using your action for anything else at that point.