Morris is NOT a better RB than McFadden. However, I think the Cowboys realized they had the pecking order wrong last season and made the change this season. McFadden is the better all-around back, like Zeke as the horse and equipped for 3rd downs. However, he's not Zeke, nor can he carry the entire load as Zeke can. So what do you actually do with Morris? He's not a viable 3rd down back, so all he can really do is give the Starter a blow on run plays. It makes much more sense to have Morris be the starting RB with McFadden as the change of pace and 3rd down back. If McFadden gets hot and Morris doesn't, then McFadden will get more snaps or series or even a quarter here and there, but we need a change of pace guy from the starter and a 3rd down back who can be counted on for blocking and receiving....that's not Morris.
Smith may even have a role in this approach as a blocking FB, screen passes, short yardage.
Of course, I'm not actually certain Zeke won't still win his case ultimately, but this seems to be the way the Cowboys are thinking about the position if Zeke is actually out.