And if you are on the wings, you have responsibility to track all the way back and help defend wide.The way I understand it, contemporary football teams defend from the front as a team. The furthest men forward are charged with leading the press and calling it off to an extent.
Also, we can shit on Sweat and Lewis for defending concurrently. We're that good at shitting.
Plus, there is nobody to play in front of Sweat at the moment. Not the same with Lewis, especially after the formation change.