Not real sure what purpose that link served. Recruiting "rankings" are by-product of on the field success. Teams that have success tend to have higher rated classes because these recruiting analysts see the team's success and then by default put their rankings higher. They rationalize that Nick Saban, Urban Meyer, Dabo Swinney, etc have had great success so the players they're after must be pretty good so those players are rated higher than others. It is at best an imperfect system.
Let me ask you this: How do you realistically rate the top 20 LBs coming out of high school in the state of Florida? The top 20 RBs in Texas? The top 20 QBs in California? How do you give a #1-20 ranking? You take a wild guess or throw darts at a board. The #1 player at a given position is often not the best. Players mature and develop at different rates. Coaching, coaching scheme, coaching changes, a player's work ethic, individual attitude, staying injury free--all of these things either help or hurt a player's developmemt.
To merely point to recruiting rankings, which is nothing more than someone's opinion, as the sole measure of "talent" is just plain lazy. Talent to win at the college level and NFL draftable talent are two very different things.