The problem with the offense is we're one 34 year old bad back away from Brandon Weeden starting.
Defensive checkmate.
The best player on defense this year should be the offense, much like it was for Denver last year. The key, as you said, will be staying relatively healthy. I feel pretty good about the WR core as long as Dez is on the field. I could say the same about the core of Rb's, with Demarco Murray staying healthy. And T. Smith is critical to keeping Romo on the field. In the salary cap era, it's really hard to expect guy's to come off the bench and not miss a beat. But if the Cowboy's can finally catch a break in terms of injuries, this offense should be good to really good this year.