Ok, when I look at personnel, it would seem Dallas' offensive line should have been downgraded from last season:
LT: Upgrade. Flozell Adams is better then Torrin Tucker, but not as good as he used to be.
LG: Downgrade. Kyle Kosier got pushed over by Lavar Arrington. He sucks. Larry Allen was a perennial All-Pro
C: Same. Gurode was here last year and this year.
RG: Same. Rivera was here last year and this year.
RT: Downgrade. Colombo hasn't played football in years, and Petitti was rapidly improving at the end of last season.
So overall it would seem this line should be worse, not better.
How did they improve, and our line downgrade even though we kept the same personnel as our dominating line from last year?