You can't guage anything from preseason games, though fans will never cease trying.
It's a mistake to try to measure yourself against another team in preseason. Teams are holding out key players. (TO for example for you guys, LT, McNeill, Gates, and Castillo for us.) That's pretty significant, don't you think? They play base defenses and offenses. How can you honestly gauge yourself against a team when you're not really playing that team and the team you're playing isn't "playing to win?"
Do you think Chargers defense was giving it all they had early on? I don't think that any more than I think the Chargers saw every blitz package the Cowboys are keeping under wraps.
We have this same thing going on at the Chargers' board. "OMG, we can't stop the run!" or, "OMG, we beat the Cowboys by 14!!"
It's glorified practice and if you take the attitude that it's completely, utterly useless to make any predictions based on preseason you will find yourself making a lot fewer completely utterly, useless predictions. Your first-string offense played better than our first-string defense. You know who else's first string offense dominated our first string defense last year? The Cardinals.
Obviously I'm not saying you guys are the Cardinals, but people really gotta learn that preseason is "non-football." It's just a way for players to prepare.