I think you are making a lot of assumptions about a "feature back".
In 1994, Lawrence Phillips led the team with 286 carries (41.6% of all carries)
In 1997, Ahman Green led the team with 278 carries (36.8%)
In 2010, Helu led with 188 carries (29.6%)
In 2012, Ameer led with 226 carries (34.4%)
There carries were more spread out in 1995 because the subs got a lot of playing time when we were up 40 at half time. But my point is that in the 90s the carries got split between more backs. In the 2010s, instead of the touches going to backup running backs they went to starting receivers because the offense was more balanced. But the touches were still getting spread around in a similar manner.
I think there is a tendency for people to discredit our offense in recent years because the overall results we're what we wanted. The game has changed and that plays a part in the statistics. None of the recent backs were Mike Rozier or Lawrence Phillips. And a step below Ahman Green. But when you look at the other members of the all-time Top 10 rushing list - Calvin Jones, Ken Clark & I.M. Hipp - I don't know that I'd say Helu, Burkhead and Ameer were giving anything up to them.