I wonder if Benn and Seguin looking pretty poor the last couple of weeks has to do with Radulov doing so much of the dirty work on that line. He's the motor - does a lot of the forechecking, digging pucks out of board battles, can be physically imposing, etc.
They used to play that way themselves, Benn especially, but maybe they got complacent with Radulov doing such a tremendous job of it. Benn seems to be picking up those aspects of his game a bit more now. Hopefully that's for the best.
Maybe separating them more often would benefit everyone greatly.