As I mentioned in the Fantasy Roundtable the other day, Dillon has actually been a more reliable guy to get 4 or 5 yards than Maroney has been.
The majority of Maroney's carries have been for 2 yards or less (with many at no gain or for negative yardage). His success has come from big gainers and highlight reel runs that Dillon WON'T get.
This past week Maroney had 18 carries for 38 yards against the Phins and a couple weeks ago had 12 carries for 18 yards against the Broncos. He's far from a sure thing from week to week.
Bottom line, if the Pats are winning, Dillon is not going anywhere unless he gets hurt. And IMO, there's as much chance that Maroney gets hurt as Dillon. Yet no one is saying Dillon is a Top 10 back if Maroney goes down (although we should be).