His list doesn't break down individuals, but rather, the cornerbacks position top to bottom within the team.
The Steelers had the league's top scoring and pass defense last season, and that was with a maligned pass rush that produced just 35 sacks all season. On the other hand, the defense as a whole produced just 15 takeaways all season, one of the lowest totals for a playoff team in NFL history.
But simply looking at a group of cornerbacks' ability to prevent the ball from moving downfeld through the air, it's tough to say the Steelers had a bad season.
The sum of their whole was greater than the sum of their parts. The marquee cornerback, veteran Ike Taylor, played very well at times and not so great at other times. The youth of the position generated much more positive buzz than negative, as CB Keenan Lewis got on the field often as starter William Gay moved inside to cover the slot. Cortez Allen played a bit in the second half of the year as a rookie, covering well both outside and inside.
While the list is written based on last year more than where teams are going, it looks pretty solid, top to bottom. I'm not sure I'd place the Steelers behind Seattle or Kansas City, and I'd have Houston much higher than eighth, but I don't think the top three are in question at all.