If you look at the OL and DL collectively -- I'm not sure there is a single team in the NFL that was worse than the Cowboys. At best, they were in the bottom 5.
So they loaded up on the defense backfield in the last two years or so -- contract extensions for Scandrick and Sensy. Signed Carr to a $50m contract. Moved up in the draft and took Mo. They invested HUGE in defensive backs -- at the expense of other platoons on the team.
It's essentially whack-a-mole GM'ing.
I don't think the front-office has done a good job overall.