It's a mixed bag. With a young and somewhat prone to injury Qb, a quality center becomes somewhat more important. On the other hand and I disagree that there's not that much difference between a good and great Cb - a great Cb like Revis is that because he can mostly play single coverage, bringing flexibility to the rest of the whole D. A good Cb I would define as such as one who fits into your defensive coverage schemes but isn't good enough to play man most of the time.
