When was the last time you saw a 240/250? pound kick off returner? Here we have another one of those big and fast backs. But he is the biggest fast back I can think of. Bo Jackson, Herschel Walker, Marcus Dupree were all sprinters but they weren't over 230 pounds. Dickerson, O.J and Peterson were/are between 210-220.
The closest thing to Blount I can think of is an old AFLer named Carlton "Cookie" Gilchrist. He was a 250 pound fullback and the first AFLer to have a 1000 yard season, he was rather unique since he went straight from high school into the CFL and then the Buffalo Bills. He had good speed but not like Blount, he didn't return kicks.
Has the league woke up to....it's hard to stop a solid running game for 60 minutes? Something they knew way back when. Who can name those Lombardi Green Bay Packer receivers when they were winning everything?