I really don't see anyone, including myself, attempting to lower the bar; but the measuring stick should make sense. The only stat you seem to care about is yards per season and how they compare to other runningbacks from previous seasons.
I asked this in a previous response to another poster: If Running Back A runs for 85 yards against the 85 Bears and Running Back B runs for 150 against the 85 Bucs, do you immediately assume that running back B is the better back, despite the fact that the 85 Bears were one of the most dominating defenses in the history of the NFL?
Therein is the issue with looking at yards per season alone; particularly when from different seasons. The truth is you really can't compare the two runnings backs with those stats alone. You need other stats to compare such as Yards after Contact, Ball Security, Pass Blocking, Catching, TD's (especially TD's, which is perhaps the most important stat as far as trending analytic's are concerned), number of carries 10 yards or more, 20 yards or more, etc. etc. I'm sure Erod could add to that list, but to go on draw's me from my point.
The point is, I really don't care if he is better than Murray...I think I already know he's better than McFadden, particularly for the scheme the Cowboys want to run. What I care about is rather or not his addition helps the Cowboys get back into the playoffs and hopefully make some waves.
Admittedly, my aspirations for the Cowboys do not extend beyond the playoffs because the defense needs work. I understand that completely. By that same token, I would not be surprised in the least if the Cowboys establish themselves as a serious contender, with or without a great defense. On this, we will have to wait and see. But on this point, I still believe the Cowboys made the right decision in drafting Zeke at 4 because he stands to contribute the most to the one stat that trumps all stats in football: wins and losses.