Brawn wants to be top dog hence why he left merc with Mattiacci still there i cant see Brawn taking the job it would be merc mk2
Everybody says that here, but I just don't get it. Brawn may want top dollar, but I think he would prefer a pass on the job of being in front of the press and the boring admin part of team principal. He is an engineer, and one who looks particularly uncomfortable under public scrutiny. He may want more power behind the scenes to make decisions on drivers, tech team management, race team management, that kind of thing, but I personally think he is more at ease with someone else answering the questions in front of the camera.
I think he left Merc because there were going to be too many chief's. As well, I think others saw him as a threat to their own power within the team, and at the end he didn't have much choice.