PHOENIX — At first, head coach John Harbaugh did not mention the name of the most important player as he was detailing the identity he wants to see for the offense the Giants will put on the field. He mentioned “high-powered’’ and a unit that “scores a lot of points.” Nothing too groundbreaking there. He stressed the need for a system “elegant enough to handle all the complicated things that go with attacking defenses nowadays, but simple enough for the players to operate it in action, in