The simple answer is yes. Contrary to popular belief, the problem with the Dallas Cowboys in previous seasons was not Tony Romo. He was a problem, but only a slight problem. Truth be told, the Cowboys have always had several things going against them that transcends the play of a singular player.
On paper, they have one of the most talented teams. The main problem has always been their inconsistency. One week, their defense will play great but would not get any run support from their backs. Or, their running game will be excellent but the defense and Quarterback will play mediocre. They seem to only play on the same level a few times in a season. When they do, they win and win decisively.
So if the Cowboys can put together a season where the offense, defense, and special teams are firing on all cylinders at the same time, then they are a legitimate threat in the NFC.