The 49ers offense sucks just as much as our defense. Here are the teams they scored more than 30 points against last year: GB, STL, HOU, TEN, JAX, TB, ATL, ARZ. One decent defense amongst them.
They totaled 39 points in 3 games against Seattle, 32 in 2 games against Carolina, and were held to single digits in 1 game by each of those teams. They managed only 7 points against the Colts.
There is no reason - other than buying into hype machines - to think that the 9ers are going to roll over the Cowboys...especially without the guys that they are going to be missing. The 9ers have just been the beneficiary of a terrible NFC and make sure not to beat themselves against inferior teams. That's the only thing that has set them apart from teams like Dallas, Philly, ATL, GB, Car, etc. in the past couple of years. They've got no explosive playmakers and a defense that has lost a step.
I'm not going to make a win prediction, but I would be far more surprised to see SF win in a blowout than the cowboys.