It's what Shanahan does.
He came in from day 1 and said this is the plan, and went about building it. It took three years to get the right players in place but it's done and they'll be one of the better running teams in the league while he's there. Zone blocking is easy and unique and you can get away with not having blue chippers to do it. Just get on your man's hip and ride him to the sideline.
OTOH, Jason Garrett has been here for six years running the offense. We've screwed around with the offensive line, invested resources in it before deciding in year 5 that we're bringing in Callahan, swapping our tackles and running some zone blocking ourselves.
One coaching staff had a vision, and focused on implementing that vision.
The other chases it's tail in futility. I can't wait to see what next year's "Hey what if we tried this?" idea is.
victory is ours