I think you have to be very careful about small school players, no doubt. But look at players like Rice, Randall, Payton--hall of famers. Heck, you have to be careful drafting big schoolers as well. I mean, in your post, you mention early first round disappointments from Florida, Virginia, and Ohio State. I would disagree with the logic--if you intended this connection--that a guy drafted 200 picks or so later than these you mention is a bust. Here is a question for you and I don't know the answer: If Johnson had been drafted in the first round with the others, would he still be on a roster?
Compare him to Gholston. Both have freakish numbers. In Gholston's defense, I am not sure the system didn't play some role; Johnston has had opportunities in two systems.
I like the point this raises. Players like Jarrett sticks around for three-four years because the team is waiting for him to develop. A player like Kenneth Moore has improved every year and is better than Jarrett right now, but he is more likely to be cut.