Picard is the captain of the flagship but we've seen in TNG "Chain of Command" that the ship can be changed over to another captain quite easily.
Do you actually watch
the episodes you cite to back up your arguments? The change in command you're referring to was not an action taken to discipline Picard but a means of assigning a commander experienced in dealing with the Cardassians to the Enterprise
while the ship was in close proximity to Cardassian space. It was not a change made lightly, nor was it meant to reflect poorly on the Enterprise crew. Had it been, Jellico would likely have remained in command following Picard's return to Federation space. But don't let facts get in the way of your assertions.