I don't see the point. Your safeties are near useless in terms of stopping offenses from 1st downs if your front 7 is weak like ours has been. And CB's even more so. In the specific case of Will Johnson, I'm weary of a secondary player who had success with Graham and Grant in the face of QB's all day, every day. To take a corner with a weak front 7 that can't stop the run feels like a very low return value for a 1.9 pick even if he does turn out to be all that everyone claims.
Yay! you can cover 1 WR over near the sideline while the opposing team just runs up the middle, passes over the middle, runs to the other side and the QB has 3+ seconds to pick his nose in the pocket then throw a pass.
I'm just not seeing the value.