Did anybody see Aaron Ross last year? He made some rookie mistakes, but also made some big plays. Just because every rookie doesn't start, doesn't mean we can't get lucky.
Did you read the thread? At no point has anyone ever said rookie corners can't contribute or start. The whole point was that with our depth we do not have to pick a CB for "immediate impact" and can afford to take the CB with the highest ceiling and most potential even if they don't start in year one.