I played a version of this for years in television news. I was an executive producer, and the news director and I ran a good cop, bad cop arrangement. People did not want to go to her, so they came to me. I would smooth it over, or I would advise them how to handle her, and then advise her how to handle them. It worked. I was good at it.
What I could not do was keep her from becoming the villain. That is what the arrangement produced, whether either of us wanted it or not. And it did not serve me. It came back as disloyalty.
It was a dangerous game, and in hindsight I wish I had not gone there. But I did not know then what I know now.