Because Maroney isn't LT or LJ, and he's not in those types of situations (with the OL those two had, and the FBs those two had).Defense is important, because when New England has a good defense, they run the ball a LOT more than when their defense is bad (see 2005). Because of that, the defense is going to have a huge impact on how Maroney fares statistically next year. Garbage time stats are a very underrated thing.
New England's absolutely decimated offensive line and Corey Dillon (injured) playing in just 12 games, and playing thru injuries in a few of those 12 games, probably had as much or more to do with their running game being less effective in 2005 than their defensive losses did. Fumbling through RBs like Patrick Pass, Heath Evans and Mike Cloud while both Dillon and Kevin Faulk (8 games played) were out, were also contributions to a lesser running game in 2005. Offensive lineman LT Matt Light broke his fibula in September to end his season and C Dan Koppen was lost in November for the season with a shoulder injury. Those were the two best offensive lineman the Patriots had in 2005. Nick Kazur (rookie) replaced Light for a bit, then got injured, which forced Tom Ashworth to move over from RT to be the Pats 3rd starting LT of the season. Their pass blocking remained fairly stable in 2005, but their YPC running the ball was among the lowest in recent years...in showing the effect of losing their two best lineman for the year had on the running game. The line was also hit with several other minor injuries through the year as well. Last year was hardly a picture of stability when it came to the Pats offensive line and running backs.