No one is gonna like this opinion but they got incredibly lucky in the first 2 rounds. But if you follow your board.....you are allowed to get lucky.
Not all teams are prepared to take advantage of "luck".
Before McClay was running the draft, the Cowboys probably wouldn't have taken a WR. They likely would have taken a CB or pass rusher this year at #17.
In the 2nd round they probably had Diggs rated as a 1st but they stayed patient and didn't trade up.
McClay preferred TJ Watt over Taco but Marinelli convinced them to draft Taco. It always felt as if Marinelli did the equivalent of fans watching highlight videos of player and then become infatuated with that player.
One of McCarthy's first statements was "Get good players and we'll adjust the schemes to fit the players".