Understood. For me, the term "great" of GOAT gets way overused. How do you define the position and who really provides those things at the highest levels? I'm looking for the total package.
Riggins was extremely productive, but he wasn't a great running back; he was a highly effective bulldozer behind a dominant offense line. E. Smith kind of fits in there, too, but with more explosion and wiggle (thought not a ton of either). Franco Harris wasn't great, by my standards, at anything. Same with Leveon Bell, despite all the talk about his patience. He is a very versatile back at a time when that is a huge asset and Pittsburgh backs tend to be stat monsters. OJ and **** were outstanding power gliders. Barry had ridiculous escapability. Earl, Eddie George, and AP hurt you and moved the chains, but were no threats to catch much. Payton is kind of in that group, though he was smaller than those guys. Faulk was the perfect fit in the Ram's offense, but he wasn't a short yardage machine. LT may be in the Allen conversation, at least for me. Curtis Martin may have been the slightly lesser version of those guys. Terribly under-rated. Bo was a comet; he blazed across and I'm still not really sure what I saw, but it was awesome.
I'd say lots of really good backs, but very few great backs.
I'll also say that a healthy Frank Gore would have been amazing. I think he might have gone down as the best runner I've seen, though I don't think he would have been the most complete running back.