While I agree, I would point out that the game also benefits from having an expert in such things that is better at it than other martials. So, while I agree that the BM creates meta issues that negatively impact gameplay, I think it’s important to have in the game.
I would just say that any successful attack that succeeds by 5 or more, or is a crit, can do a manuver as part of the attack. If an attack against you fails by 5 or more, or is a nat 1, you can do a reaction maneuver (mostly a riposte obviously).
The BM can do manuevers on any successful attack, and add extra damage if they spend a die when doing so, because the die represents extra effort to execute the move perfectly or with particular ferocity, etc.
This way, the BM exists as the expert in tactical combat, but your barbarian can goad and trip and such without sacrificing damage.