If you whiff on some quality candidates and have no other top notch hires to approach. You SHOULD do one of 2 things:
1) Identify a decent individual on the current staff that can take the reigns, give them a 1 year contract at a small price and then tag them interim while you wait and continue to work on things for next offseason. If they end up doing great, perfect. If not, its not a huge loss, just a season and you actually saved money while really getting your ducks in a row for next hiring season.
2) Identify a coach who doesnt have the stellar wins/loss record but is known as being a top notch recruiter and bring him in on a mid level paying 3 year deal. Let him stack the cupboard. If he ends up doing great, again, great. If not, you havent broken the bank and now you have a stockpile of talent to showcase the next group of hotshot coaches making yourself MUCH more appealing to the big time guys.
What you DO NOT do is hire a middling coach who doesn't do much of anything any better than the guy you fired; not recruiting, not winning, not anything really. And if you do end up making this awful mistake, you don't double down on stupid by giving him a long contract with top 10 coach money guaranteed. Do this and you wont stockpile talent, you wont see a big difference in results on the field, and when it comes time to move on from the failure, you look no better than you did before and you have less money to offer. This option is foley level incompetence.