The only argument and best argument to make against Barry Sanders is that he's a boom-or-bust running back.
1. Barry Sanders wouldn't take a 3-yard gain; he always wanted the home run, which is why you see him dance around behind the line of scrimmage all the time.
This type of running is not conducive to winning. If your team is up by 4 points with 8 minutes left in the game, you need a long drive with several first downs to kill the clock.
At running back, I'll take a consistent 4.5 yards per gain over a running back that has rushes -3, -2, 20 yards.
With Barry Sanders placing his team in 2nd and 13, it's almost a drive killer. Even if Emmitt Smith's Cowboys didn't get a TD, the Cowboys would get a couple first downs and punt from midfield instead of their own 20...very key in winning the field of position battle and the game.
Just like a QB...you need a QB to get the first downs while avoiding INTs. Throwing 35 TDs and 20 INTs is not good.
2. Barry-supports will cite that Barry Sanders had a horrific offensive line. His offensive line was not as heralded as Emmitt's, but Barry Sanders had a few Pro-Bowlers on his line - Lomas Brown, Kevin Glover, etc.
There were much worse OL's than Barry Sanders. Cincinnati's Corey Dillon comes to mind.
YET...Barry Sanders leads NFL History in negative yard rushes. This is not because of his so-called horrible OL, but because of Barry's running style.
3. Emmitt Smith played in the toughest division as well. Facing Jerome Brown, Reggie White, Seth Joyner, Brian Dawkins, Eric Allen, Dexter Manley, Charles Mann, Darnell Green, Lawrence Taylor, Carl Banks...NFC East defenses were much tougher than the pancake Buccaneers and Bears defenses.