The only highlights you saw were when he has huge holes and runs untouched. He is a crouched runner that uses change of direction moves a lot, he is not an upright runner like Staley, Staley had an overdrive speed gear that he would turn on when he had an opening, McGrew just goes 0-60 and then is at top speed and he waits and dances in the pocket until there is a hole, he doesn't hit the hole hard. I have seen McGrew run almost 60 yards on a play before even crossing the line of scrimmage on several occasions, I can't imagine Staley ever doing that, ever, and McGrew rarely initiates contact, he will fake it, and then try to juke or use a change of speed with a stiff arm.
Saying they run similar is the open field is like saying they run the same down a track, it doesn't tell you much.
I have game planned against this kid for entire seasons, because he would kill us in every game and our team played his team in every championship game so we scouted him all year long and tried to get him back onto our team, I have watched him in slo-mo for hours, he is the opposite of Staley, trust me, outside of kids I have personally coached you would be hard pressed to find another player that I have watched more film on.