Sticking with the "it's starts up front" theory (which I subscribe to), what do we have now?
DL is pretty good, Lawrence, Armstrong, et al, no great DT but Hankins provides the beef if he's healthy and a strong DT rotation can be effective.
OL is fairly good, as long as Tyron stays healthy and Steele comes back 95% or bettter as before the injury, Martin always solid, Biadasz could be better but he's not terrible. Remember Martin was All Pro his first year, if the Cowboys could duplicate that or close to it via trade or moving up in the draft to fill the LG spot, could be one of the better OLs in the league.
With a top defense and even an average offense, as Jake noted no Brady or maybe Rodgers, the Eagles losng key pieces, Giants and Washington still needing major upgrades here and there, if Dallas can get home field (for what it's worth) then at least it's not looking bleak....