This choice your positing is similar to Mullen's 7 minute fourth quarter drive or the run in the redzone against LSU. In those situations, I would have rather seen us play with urgency, drastically increase the tempo, and keep the ball in the air, even if it totally failed. The reason, is it would give us our best chance to win by preserving more opportunities for us to score and win over the remainder of the game. We may not ultimately win, of course. But, my frustration is we know if we take our damn time and then squib kick it, our chances of victory are substantially less. We knew what that our chances to win bled as we intentionally (or willingly) bled the clock. No options when behind 2 scores in the Fourth are great, but you take the risk as a result to get yourself back to having a 20-25% chance of victory.
Well, that is how I feel about the Mullen hire. Super conservative hire, with only the slimmest of chances of turning us into a truly great team. Since you asked, I would have rather us shot for that potential greatness and thrown everything we had at Frost (even Kelly showed a daringness to it, though perhaps more suspect). Frost may not have resulted in a championship, but it would have been making the effort to try for greatness. Mullen has never felt that way, even if he will get us to "better" and "consistently good". It is a personal difference, but I'd rather that not be the goal of my team. I also wonder how Frost would have done here. Maybe the same as Nebraska, but we don't know.
Since you asked, there were others I thought showed creativity, some program building, and innovativeness: Norvell, Candle, Brown, Brohm & Seth Littrel. Taggart won at USF by mistake. He wanted to be Harbaugh, but had to adjust at the demand of his former HS coach, then OC to maximize the value of his QB. He never had his own style for anything and was never on any list I wanted.