My comment at safety isnt a knock on Roberts. I think hes actually one of our better players, certainly better than our Dline or LBs outside of Boyles. I can agree with Sanders being small though, he just cant tackle.
My point about the safeties is that it isn't certain who will start there. We have guys like Burnett, Davis, Sanders, Roberts, and Lapointe. I'm probably missing a few names here but those positions are up for grabs, as is most of the defense.
The only locked positions on defense to me are Sails, Hampton and Boyles.