Agreed and thats a risk I'd be fine with avoiding and getting a veteran in here. I havent looked at the most recent data, but as of a couple years ago it was around 10% of 3rd round players will ever make a pro bowl in their careers. That may have gone up recently with how many players drop out, but probably not too drastically. Plus a guy like Brooks even if he's a 1 year rental you have a realistic shot of getting a comp pick coming back your way.
The 3rd round is probably ideal for the team trading away if they are truly a contender IMO. You may only get a starting caliber player once every 5ish picks in the round, but its still a high enough pick to potentially land a stud player that teams will be willing to actually pay decent value for.