The zone blocking system is used by two teams, both installed by Alex Gibbs. He left a few years ago, but his system is very much alive. Atlanta went to it as well and they are also at the top of the league in rushing yards and I doubt anyone would say Warrick Dunn is the kind of guy you would get that sort of production from.
Granted Dick wasn't a huge guy, but he ran between the tackles because of good vision. I think Bell still needs to work on seeing holes instead of just finding a spot to bully his way into. Anderson for all his build has gotten very strong at seing holes and using them, even though he would gladly pound into the line as well. There is just no way though Bell will be a Dickerson-like player. He was much hyped from draft day, using the very pick Shanahan got for Portis. At least he is living up to the billing this year after being something of a dud last year.