You have to be trolling now.
You showed me the difference in conversions. And then I showed you the fact that the difference in conversion percentages did not translate over to the amount of plays the defense faced in 2014 compared to 2015.
How are you missing this?
2014 offensive 3rd down conversion rate = 2nd in the NFL
2015 offensive 3rd down conversion rate = 26th in the NFL
2014 defensive snaps = 950
2015 defensive snaps = 967
So while there was a large difference in offensive third down conversion rates, in terms of saying that a better conversion rate will lead to less snaps for the defense, it doesn't work.
A 24 slot drop in 3rd down conversion resulted in the defense playing 17 more snaps in the 2015 season, just over one more snap per game.
You keep talking in theories........... yes, in theory if the defense is on the sidelines they can rest and will be fresh. However, as it pertains to the Cowboys and this season compared to 2015 and 2014, it's unlikely that the problem the defense has is the offense putting them on the field too long.