Look, Selvie plays the WDE position better than he does the SDE spot that he manned last year. He is more than solid against the run and would have probably had more sacks last year over on the weakside than Ware did. He isn't perfect, but he can set the edge all day long.
If Dallas moves back to the latter half of the first round and takes Dee Ford to come in on certain passing downs in place of Selvie, then I couldn't find much fault with that. Ford would get to some QB's, you can bet on that. It would be a platoon just like Seattle used. Nothing wrong with that. Ford could be very valuable in that role until he grows into a starter.
Selvie could move back to the strongside on passing downs, or even inside if they wanted Crawford at the SDE spot.
Ford would offer plenty of versatility on the DL, which is the most vital area of Marinelli's defense. He has rare athleticism for a guy his size, is strong for his size and can run like blue-blazes.
I'd be fine with a trade back for him.