How about Admiral Satie? She outranked him and was older than him, and their relationship changed a great deal during the episode.
I think it makes perfect sense to have a senior captain commanding the Federation flagship.
I just saw that episode for the first time a few days ago. "The Drumhead," it is called. It is a somewhat interesting episode. That was quite a negative encounter Patrick had with Jean Simmons - I've never seen Captain Picard in such an encounter before. I've seen Michael Dorn in one (with the ambassador who was annoying him), Data in one (with the woman who destroyed the Crystalline Entity), Commander Riker in many (with his ex-captain Eric, with Deanna Troy in Gambit, Worf in All Good Things, with the current captain and Captain Picard in Gambit, in Frame of Mind, on the Klingon ship in that officer exchange program episode), but not Captain Picard. It was interesting and instructive, and only possible with someone who is his rank or outranks him, and is also his age or older. Thanks for the info.
I never disputed that it makes sense to have a senior captain commanding the Federation Flagship though. It makes sense. He wasn't exactly senior though. He wasn't as old as he looked, only 53 at the end of the series.