Riley's year, Narduzzi and Herman jump out. But hard to think Herman would've come. Narduzzi, maybe. Lot of washouts from that year. Chad Morris, Jim McElwain, etc.
Pelini's year is difficult to say because most people wanted him. Kevin Sumlin? Paul Johnson? Ed Orgeron?
Same for Frost. I doubt anyone can seriously say we should've hired someone else. Had Moos hired Fleck, for example, who looks like a great hire now, he would've been chased out of town.
The further back you look, the more you realize:
Most coaches fail.
It is hard to find a winner.
Most winners don't win for long.
Winners often leave.
Winners usually win soon.
So I guess there should maybe be less reluctance to fire someone after 2-3 years. And let's not beat ourselves up over some of these hires. There's not many guys that were obviously better, whether at the time or in hindsight.
Of course when you're playing this game you could say if we'd fired somebody sooner, different coaches would've been available etc... But that is why message boards exist.