the thing that some are forgetting is that for the last 2 seasons coming into this one, you couldnt run the ball on
osu, which forced more teams into throwing situations and spread attacks. as such, there is an increased emphasis on having safeties with good coverage abilities. With the DL coming back next year, I expect running on
osu is going to be a tough task.
while it is nice to be able to put your cb's on an island and run different blitz packages, its also a nice luxury to be able to run different zone schemes to confuse the offense and not have to worry about safeties getting burnt.
A good offensive scheme will figure a way to beat man coverage, and even the best get burnt. having both safeties and cb's that can cover, thereby allowing a defense to utilize several different schemes will only make the defense stronger overall.