It's just my opinion, but expecting them to produce same way a Dalvin Cook or Sony Michel will is unrealistic.
Georgia will likely get carries for 3-4 RBs, but Nick Chubb is the featured back - not Sony. So better hope Yearby puts up numbers comparable or better than Sony.
Sony had 400 yards last year. He shared time with Gurley and Chubb, missed 4 games with an injury, and only had 100 less yards than Yearby. Sony also ran for 4 more TD's than Yearby.
I expect Sony to have a better year as a backup than Yearby will as a starter. He's just a different level of talent than Yearby.
It's not a question of who's the better back, but who gets the most touches. The UGA backfield has more talent and more depth, including the return of former 5-star RB Keith Marshall, who was on par or better than Gurley before getting injured. You might be right, but if Sony, as Chubb's backup, outgains Miami's starter then it will be a really long season.
That's always been my argument against Yearby. He gained so many yards in HS because he was getting a ridiculous amount of carries - much more than anyone else. Per carry, his numbers don't stack up.
Keith Marshall - I feel bad for that guy. He tore his right ACL for the 2nd year in a row last September, so I don't see him as a threat to take carries from Chubb & Michel. It'll be a great story if he does, but he's just not the same back.
I think Michel & Yearby each get around 175 carries this year if their healthy. But Michel can do more when the ball is in his hands, so I think he'll have the better year.