Penning wasn't even a penciled in starter...he was a projected as a project that even if healthy wasn't going to start week 1...maybe without the injury he starts before November but that isn't the type of offensive lineman that you bank additional draft capitol to make sure you get. There were at least 2 other tackles drafted after him that contributed just as much.
My take on linemen, is that its almost all about coaching...they're all big/strong guys, coaching makes all but the elite few interchangeable.
We won the compensation part of the Graham trade, but we totally blew the pick.