No, the fact that by the time they're eligible for the draft, and of the 10-15 taken every year, there's usually little to differentiate the top picks from the worst. What separates them is anyone's guess. That's Gladwell's point.
But if you look at the top picks and the bottom picks, you find almost none of the bottom picks starting in the nfl (you named a few who did it in the last decade) and a ton of the top picks who are, or are at least second strings to superstars. I would say that means that what separates them is far from anyone's guess. There's certainly some variance there (see Tim Couch) but it's not unpredictable.
The complicating factor, of course, is all those former first rounders but second stringers, have had significant money invested in them. It's a lot easier to cut the lower picked players but not necessarily because of their "talent".
Matt Cassell = perfect example.
Does he even get a chance on any other team? Ever?
