Who said that the Cowboys didn't have one of the top Offenses? I mean, statistically, they absolutely did but in terms of how they performed against Top Ranked Defenses, they clearly did not get it done well enough to win games. I mean, that's the entire crux of the conversation. It's all well and good to throw down 500 yards against a poor defensive team and hang 46 up but if you can't score more then 9 points against New England, 10 points against the Saints, 15 against the Bills, 9 against the Eagles, it doesn't really mean anything that you are ranked as a top 10 Offense. You gotta beat teams with good defenses or you might as well be playing Flag Football.
Take a look at the top 10 Offensive ranked teams. Of the Top 10, I think only something like three of them made the playoffs. Efficiency is the mark of a good Offense, not statistics.