The Chiefs are tearing it up by using zone blocking.
Dallas' offensive line is done. Stick a fork in it. They couldn't block Betty White in the run game. This line is aging, declining fast, and slow.
If they don't replace Davis, Colombo, and Kosier next year and evaluate LT correctly, it's only going to get uglier. Gurode at center... I'd try to replace him, too. Getting another LT and moving Free to RT should be considered, and replacing both guards is a must, imo. Unless, you like playing and paying for that horrible right side of the line (Davis and Colombo) and depending on Kosier to stay healthy, you will at least replace all three of them. I'd be looking for Gurode's replacement, too.
The Cowboys have a great back like Felix Jones, and they can't open up any space or holes for him or get him to the outside.
The Raiders made adjustments for Darren McFadden this year, and he is tearing it up.
IMO, Dallas needs an athletic, mobile offensive line, that can get to the second level and hit a moving target, with the lateral quickness to stretch the defense in the running game (laterally) and give Felix Jones back-side cutback lanes. Felix Jones is a jump cut slasher who would destroy teams in a zone blocking scheme.
Davis
Colombo
Gurode
Need to get the boot...
Kosier
Needs to walk...He fits the profile, but you can't depend on him to stay healthy...
Again, this offensive line couldn't block Betty White...
Why waste your money?
Get younger and more athletic and completely rebuild the line around the skills of Felix Jones.