Part of that is we don't have a QB that can accurately throw the long ball. In Milton's first game back (I forget the opponent) Milton has coverage beat TWICE (at least those were the ones we threw on) and Purdy missed those throws both times. If you go back and watch his freshman campaign Butler simply went up and got everything that was underthrown. For whatever reason, Brock lacks the accuracy on those throws.
We don't have Lazards or Butlers around anymore to win every 50/50 ball. But as we see teams sell out to stop Hall we're going to see more over the top one on one opportunities. Besides Hutchinson, Shaw and Milton I'm guessing Porter is going to get some snaps to take advantage of his track speed.