It is really a combination. Here are some generalities:1) Some versions of the cover 2 see the WLB getting a lions share of the stats because of the way they use the MLB. In the Dungy 2, the MLB drops off to play center field and the WLB assumes some of the duties of the MLB making them the top point getter. This really explains the "studliness" of Derrick Brooks, David Thornton (2003), Cato June (2004).2) The strong side linebacker plays over the tight end and in most schemes it is his responsibility to cover him. Because the TE is often used as an additional lineman they will become a DE on many plays where their responsibility is pass pressure and run coverage. But, in reality, they get taken out of alot of plays because of this. This is why Julian Peterson is such a great NFL player but a poor fantasy player.3) In some pressure defenses, such as Washingtons, the SLB has fewer TE responsibilities and is used much more like another MLB inflating their stats. Marcus Washington is a good example here.4) Some teams, while their depth chart appears make the distingtion between SLB/WLB they don't really scheme that way. Tennessee is a good example where the LBs play a side of the field and cover the TE if he happens to line up over there. In this case, the talent factor will drive alot of the stats.