Well, technically "Break and Attack" translates to "go find yourself a target, I don't care which one", as opposed to attacking a specific target, guarding the wing-leader, avoiding combat etc.
In WC1 to 4, you are always the Wing Leader (Even in WC1, they they place you in charge of Spirits wing for 'experience'). As such, it was YOUR responsibility to complete the mission objectives, and your wingmans job to assist you, whether that be by destroying particular targets, defending you etc. It was your job as Wingleader to decide the role you wanted your wingman to play. Some wingmen, (think Maniac) would not follow those orders particularly well.
I guess in WCP you may technically be the wing leader - they just don't respect you

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