They haven't ignored the O-line.
Since drafting the third All Pro, Zack Martin, they have continued to address the needs of the offensive line squad.
The Cowboys have drafted 9 O-linemen in the last 8 seasons with their picks geared closer to the top of the draft than to the bottom. And don't forget the 2nd round contract for La'el Collins
They have used a 1st, 2nd, two 3rds, two 4ths, a 5th, and two 7ths.
The Cowboys have pretty much gotten what you would normally expect from this group of draft picks if you were to compare around the league. That's not good enough. Considering the investment into scouting and coaching, there should have been better performances by most. There has been more than the average share of injuries and issues and that has also played a part.
Since only one of the All Pros now remain, more responsibility will have to be placed on other O-linemen and it might as well begin with game #1. For guys like Tyler, Connor, and Steele, it has to be swim or sink.
With that said, the team will have to adjust and I would say that a dominant defense would be just the ticket.
The offense will focus more on quick short passes to help preserve Dak's health. Expect the TE's and RB's to take on more receiving responsibility, as well as blocking. Expect to see more two TE sets, which also helps out the WR situation. The good news is that the Cowboys are built with the right personnel to make this happen.
It's going to look real sloppy at first but we hope to see incremental improvement from a much younger offensive line this season.