It's more crapshoot than rocket science

Which is why making definitive statements either way (i.e., "coach X would have been better/worse than coach Y") should elicit little more than eye rolls.

Nobody knows with any degree of certainty who would have outperformed or underperformed vs. Brian Kelly over the past decade or so.

If hiring coaches was rocket science, there would be far fewer swings and misses. Still, I respect those who are more focused on getting things right, despite the number of strikeouts they accumulate along the way, than on continually trying to make themselves believe that maybe the guy they've got is close enough after all--and that with just a few lucky bounces, darn it, he might finally win the big one.