After watching that video I'd say he's best suited for the dual 8 positions that Silva and De Bruyne take up which are effectively like 2 #10's. Looks like he can play well between the lines, can play key passes to break a press and can assist and create while being able to get into the box a well. Of course he seems like he could play a number of positions, but that's just where I think he'd be most effective. I wouldn't mind him staying at Benfica another year and we tap him up when Dave is gone.