Like s4tch said on the previous page, his job isn't to hire the coach, I'm sure he'll have an opinion but this is down to Scanavino, with assistance from Calvo and oversight of Ferrero.
Marotta's role for almost all of his Juve career was CEO so he was directly involved in appointing the coach.
Fair enough. My point is that this mercato doesnt reveal much about him given the money and time constraints.
To your point about his responsibilities vs his bosses: Hard to say where his responsibilities end and another's begin, we will have to assume that management is a unit and they will share the successes and failures. He found success within the management group of Napoli and as a group they all shared the success. Marotta found success with Agnelli and co, and made us believe Agnelli was competent it was only later when Beppe left that we came to understand how much of a difference maker he probably was.
Beppe found success again with whomever is at Inter (no idea who they are) and they sharing the success. Tici failed here (when given the top job) and at Spurs, and shares the failure with Levy and Agnelli.
In short, we expect them to work together and can judge them collectively and individually by the final output. If he fails here but succeeds everywhere else then we have more data to discern who's good and who's shit but until then they are all accountable to the results.