Well maybe because Perkins is not an all down back. McCaffery would help our running game, passing game, and return game. He could get 10-15 carries, 5-8 catches, and 3-5 returns per game. He is the most versatile player on offense in this draft. Plus he has wheels.
McCaffery wouldn't be my first choice, but he is a damn good player that will do well with the Giants. I would have no problem if they decided to pick him.