Yes, because of the players they had they still had one of the better offenses, but what history tells us is that there are three ways to win Super Bowls: Have an elite offense, have an elite defense or have a balanced team (both in the upper half/top 10). I believe we had a few years where we had the components for an elite offense and Garrett's philosophy held us back. It was still good enough to make us a playoff team, but then we couldn't contend because we weren't innovative against the better defenses while their offenses beat up on our defenses.
If Garrett/the Cowboys had focused resources on the defense, we wouldn't have had that offense. And then when the Joneses forsook free agency, there was no way we were going to have both at the same time. I also think some of the DCs may have looked better here if they'd had better players to work with. I mean, most fans wanted Quinn ran out of town after last year's playoff performance, but there's only so much you can do when you are dealt a bad hand.
