Even the "tough" sec "schedule" is overblown. The last time I looked Kentucky, Arkansas, Auburn, Missassippi, Southern Missassippi and Tennessee were all in the sec. Perhaps they can strengthen their schedules if they add Kansas and Washington State. Until they do this, they will just have to suffer and keep avoiding any outside challenges unless they have a month or two to prepare.
As for that big full back: kinetic energy equals 1/2 mass times velocity squared, or to put it another way, force equals mass times acceleration. (Or fron the defensive back's view point, the force to stop the sums-er-bitch, mass times deceleration; to neutralize the big guy's kinetic energy [i.e., get him one at rest on the ground] the defensive back must generate an equal amount of KE. )
This is why we need a jumbo backfield of Nix, Eifert, Truit and Day.
My last exposure to physics was about fifty years ago, so I may have some of the equations wrong, but I still think it is easier to stop a bee going fast than a cement truck, even going slow.