I think that's a cop-out. The good guy, bad guy parenting is damaging, IMO. Theres power when the parents agree. Once a kid knows they can play the 2 off each other, it gives them the power.
Occasionally mine would take over. But then he would put my son up against a wall and I was not putting up with that. He only did it in front of me once and I flipped out. That night I told my son to not come home, he was probably punishing me for disagreeing with his tactics before.
Like, put him up against the wall and he'll listen to you? The old "let her handle it and see how she does."
Anyway, that was a long time ago. He's 32 now.
I'm not super close with any of my kids and sometimes I'm sad about that.
I try.