If you paid attention to Dumervil this past season, he did not struggle at all against the run. He led our defensive linemen in snaps and played with good leverage as a run defender. It's just easy to say he gets destroyed against run because you don't pay attention and then assume things based on his size.
Here you can listen to Tom Nalen and Mark Schlereth discussing Dumervil's contract situation and both compliment Dumervil's performance against the run this past season.
Jack Del Rio also praised Dumervil's run defense.
"Elvis and Von have both embraced playing with the kind of technique we need them to play with to hold up against the direct run at them," Del Rio said. "You know people are going to do it. They're both guys that despite their size, they play with great leverage and technique, which allows them to play against bigger guys."