I don't think that is very accurate. Only a handful of guys have had consecutive seasons with 400+ touches.
James Wilder did it. He really didn't get a heavy workload his first 3 years in the league. He then got 400 touches his 4th and 5th season at ages 26 and 27, respectively. After that he returned to not so heavy workload.
Terrell Davis did it and then blew out his leg.
Ricky Williams did it. He had other issues.
Curtis Martin, Edgerrin James, Eric Dickerson, Walter Payton and Emmitt Smith all had stellar careers after having consecutive seasons of 400+ touches.
The season isn't over and maybe Elliott doesn't get 400 touches this year. He is sitting at 333 touches. And who knows if he gets 400+ touches next season.