How to deal with egos?

Power shifts during mergers are inevitable.

I work for a team who is on the "outside". The bank merged with another about 4 years ago. The new CEO brought in his people and they've brought in their own people at various levels. Day to day, I work within an "insider" office on an existing "outside" team. This team has rejected my senior teammate who tired to transfer over. I've been told there's an "inside" spot for me in the future by senior leaders but that position has failed to materialize, and honestly idk if I want it now.

Over the past few weeks, I've seen the mid level manager on my team preform and do what it takes to meet our clients needs while the mid level manager in home office scoffed at the "junior" work sent their way. He's a slack ego ridden tumor on our organization, in my opinion.

Our MD is a bit toxic and it really hurts our mid level leadership. How can I convey the potential of my mid level managers to seniors on another team without betraying my own senior manager? Its already an open secret people wanted out. My MD brought me on knowing I'd be in the other office, I almost think he did it to leverage my relationship with this other team to get his mid level guys into decent jobs. He's set to retire soon.

The "inside" has all but blacklisted my mid level managers for absolutely no reason, they're really good guys. I got took in out of the cold with this job, so grateful for the opportunity but it's such a weird spot to be in. I have been given a weird amount of knowledge for my level by both sides.