First off Both Leon Hall and Brent Grimes were very good cb's before they tore their Achilles. They aren't the players they once were before the injury. ( still both are rare players that come back from that injury- more exception than the rule) Dee Milliner was never very good prior to that Achilles tear, and now losing some ability due to that injury - do you really like his chances to develop into player the Jets envision when they drafted him number 9. Jets will be very patient with him , and I will be surprised if he's a go by training camp. ( no need to rush him as he way down the depth chart- need him more down the road). maybe see him eventually moved to safety.
The Jets need Mcdougle this year, and are counting on him to be contributor to their secondary. Like a lot of young Cb's it's paramount he stay healthy all training camp.( Only way you get better is by getting the reps)
Grimes made all pro for the first two times in his career after the Achilles injury. Hall has always been a good, not great CB. I don't agree that they aren't the players they once were. Milliner may very well be a bust, or at 23, he could still have a good career ahead of him. At this stage, I agree with you that he is not likely to be the player that he was drafted to be at 9, but he could still be a player, and of course I would prefer if he were not coming off a major injury. An Achilles injury, however, is no longer an insurmountable injury for a pro athlete.
I don't agree that the Jets are counting on McD to be a contributor this year. Revis, Cro, Skrine, Walls, Williams are all likely ahead of McD & Dee on the depth chart. I am hoping both guys can get plenty of reps in TC -- as young CBs they will need it. He is a 3rd round pick coming off 2 years out of the game due to injury. I really don't think they are counting on him to be a major contributor. Let him get healthy, learn the pro game, work into the rotation a bit this year and see where he goes from there.