Pre-Nebraska, Frost's resume was about as good as you could possibly get. He played under Bill Wash and Tom Osborne, for whom he won the national championship. He was WR coach under Chip Kelly, was the OC for Oregon after Kelly went to the pros, then turned a winless UCF team into an undefeated one in a few years.
It's true that he **** the bed at Nebraska. And many of his games were sub-30 ppg. I don't have an explanation for it. His recruiting wasn't good, but it wasn't horrific either. You would think he was capable enough to score more.
Frost would be 10x the OC that Gattis was. But I definitely see the risks. I would rather have Mullen or Brady if either are even realistic names. He'd be in my second tier. But I could understand why Mario would find Frost to be a potentially good fit.