When you’re evaluating cornerbacks, there’s a lot to take in. Is this cornerback better in man or zone? Does he have match feet, Can he run the receiver’s route for him? Is he sticky in all phases of coverage? Do his eyes match his feet? What are his transition traits? On and on and on.
It’s a hard thing to get right, which is why you should always ask someone who knows more about the position than you do, if you are able.