I definitely think that they miss Long. But I said this before the season, and if you watch Fisher's Press Conference, he makes a point of saying the same thing. Teams know this team can pressure the QB. They are game planning to get the ball out quick.
I am not surprised that the sack numbers are way down. But I am surprised at the lack of holding calls against offenses. Go back and watch the long TD play to D. Bryant. They literally yanked Langford down from behind as he was about to hit Romo just before he released the ball. Quinn gets double teamed..... and more often than not, one of the two have to use an arm bar to hold him while the other guy chips him.
The other problem, is they haven't been able to stop the run, which has made it possible for teams to limit the number of passing attempts. Even while racking up 34 points (27 by the offense), Romo still only threw the ball 23 times.