Calls for an "immediate impact" at CB through the draft. Do they make sense?

I'm talking about current situations with rosters, not just saying good teams don't start rookies. I was using that as an example because better teams usually don't have a ton of holes to fill. We don't either so its going to be hard for a rookie to come in and start at most positions on this team.

What defense were you watching last year?

We have holes the size of canyons on defense. But you want to draft a "potential" bench sitter with our first choice.

What gives?