Did any of those guys ever approach 30 total TDs? Different era -- I'm not sure they would get you the fantasy points that today's RBs do against these porous defenses. Remember, Faulk and Holmes were breaking statistical records even though they were not, in my estimation, near the calibre of Brown, Dickerson, Sanders, or Simpson.
You could ask the question, what guys dominated their era? That would put guys like Brown into this fantasy argument.