Sorry buddy but all the work is done for him, that's what offensive coordinators are for, the plays are picked for him and the scrimmage is set for him to pass to the most open player, all he has to do is make sure that the play is run well(Which he has no control of) it's all orchestrated to make the defense guess and trick who is the primary target. If the defense gets it right and covers that player well then that is the only time he actually has to do work and improvise a bit on either to pass to a different target or run the ball. The New Englands have an elite offense and a coach who has been coaching them forever, Brady is good and I won't deny it's he's one of the best to play that position, but again the position is overrated to the max. There's no athleticism involved, all what you've stated involves thinking and strategy which all are done for him via the offensive line and drilled into him during the practice week.