This is pretty common when we like the results better. "It had to be because we were doing something different." No, it doesn't. Just like everyone was falling all over themselves to praise McCaffrey after the Penn State game. It wasn't because our QB play was any better. It was probably worse. The results were just better so it SEEMS like things were better/different.
For the year, Mills ran:
Left end - 12 carries
Left side - 8 carries
Middle - 24 carries
Right side - 20 carries
Right End - 19 carries
So nearly 2/3 of his carries for the year were between the tackles.
He explicitly did get "cute" with Hickman on the goal line.
I don't think the issues is we don't have a serveable backup. It's that they're all freshmen, didn't have spring ball, barely had fall camp and were all injured at various points during the year. We also got somewhat unlucky that both Washington and Bell turned into head cases. We're still playing catch up and injuries are making it really tough.
You can argue that all you want. The facts are we have the #28 rushing offense in the country and the #10 rushing offense in the Power 5. Yet people are trying to say that Frost doesn't run the ball. It's simply complaining about anything and everything when you don't like the overall result.