Raheem Morris, the Tampa Bay Buccaneers' head coach, was a defensive backs coach before his sudden promotion to defensive coordinator and later head coach. Perhaps this explains why the Bucs seem to have taken the attitude that hoarding defensive backs is a great idea. We already knew that the Bucs thought they couldn't "ever have enough cornerbacks". But somehow, they seem to think that more safeties is a good thing as well.
Look at the logjam the Bucs have created with young, talented but raw players at those positions. At cornerback, Ronde Barber and Aqib Talib are the clear starters, but with Myron Lewis, E.J. Biggers, and Elbert Mack the Bucs have three young cornerbacks behind them with game experience. And then there are D.J. Johnson, who spent most of the year on the practice squad, and seventh-round draft pick Anthony Gaitor. At safety, the Bucs have Sean Jones and Cody Grimm as starters with Tanard Jackson returning during the season. Behind them the Bucs have Corey Lynch and Larry Asante with playing experience, practice squad players Vince Anderson and Dominique Harris, as well as fifth-rounder Ahmad Black. That's a lot of young defensive backs.
This hoarding of young defensive backs allows the Bucs to create competition among less highly-touted players to improve everyone, and let the best players shine. Of course, that competition has somehow also gotten Elbert Mack significant playing time, so it's not exactly the most effective method.
Aside from competition elevating players, the Bucs also have a set of excellent defensive backs coaches in current head coach Raheem Morris and current actual DB coach Jimmy Lake, both of whom have coached up some obscure players and gotten them to play well. The combination of competition and quality coaching has allowed the Bucs to perform well as a pass defense even when missing their most talented players like Aqib Talib and Tanard Jackson.
With the league moving to a more pass-oriented style each season, it seems clear that a good pass defense is key to sustained success. To have a good pass defense the Bucs need quality defensive back play, and they have managed to get just that. But the trend so far has been to rely on young players that need to be coached up, instead of blue-chip talent or quality free agents. It has worked, but I wonder whether the Bucs can keep this up in the long run.