I hate to say it, but If I could add 1 pro-bowl caliber player to the Cowboys it would have to be Edge. A 10-12 sack guy would probably make the greatest impact right now.
But OT, LB, S, CB and TE would all make a huge impact.
When Dallas drafts next April this should be their mindset. Find an all pro caliber player regardless of position. If they are drafting in the top 5 I think it has to be LT or Edge depending on who is available. If there is a Tyron Smith in this draft, take him. Move Guyton to RT and waive Steele.