Some might argue that adding another elite cover corner will do the Jets defense no good without a pass rush. I do not agree with this. A pass rush and coverage are related. One helps the other. Improving a pass rush forces the quarterback to get rid of the ball quicker and forces the corners to cover for less time. Good coverage gives pass rushers extra time to get off their blocks.
When the Jets have had success getting to the quarterback under Rex Ryan, the coverage has had a lot to do with it. It was true in 2009. It was true in the 2010 Playoffs. Shaun Ellis' sacks on Tom Brady were not immediate. The Jets only rushed three on those plays. Ellis had to fight through double teams, which took time. Because the coverage was good, he eventually got there.
Adding a guy like Asomugha would allow the Jets to run an enhanced version Revis Island. Darrelle Revis usually lines up against the best receiver on the other team by himself, which allows Rex Ryan to stick everybody else in passing lanes for the other receivers, making throws a tight fit. Adding a second corner would allow the two of them to take the outside and clog the middle of the field for the other three eligible receivers. That is what the Jets did in the Divisional round against the Patriots. Receivers not getting open would give pass rushers more time to get there.
As I said in the last post, one must consider money and other aspects of the team that could be neglected if the Jets used too much space at one position. The notion, however, that adding a second great corner would be useless without adding to the pass rush is mistaken in my book.