Wr positions

Where does each of our starting 3 wrs fit in the scheme. Dan Orlovsky has suggested that Tank is the slot wr with deep speed, Nico is the big boddied X and Stefon would be the route technician Y. My take would be Nico is more the deep speed threat, than Tank and Stefon would be more of the big boddied X who sits in zones. I believe Tank is more of the Y. What are your opinions on this?