JMO, I think Mullen is a safer hire but Fuente has higher upside.
I think Mullen would be 8-9 wins a year. I think he is a below average recruiter for SEC. Solid coach and, unlike our current coach, develops and gets results from his guys. He'd fight for East, win a few times, but I don't think he'd ever win conference. And we'd have to pay 5.5 million (or so. He makes $4.8M a year now) for that. That's the main reason I'd be against it.
We could hire Les for under $4M a year and get, at least, same results. I think Les would win east more and would sneak a SEC title or 2 before retirement. Make the playoffs a few times.
Fuente is a bit of a gamble, but getting to ACCCG year 1 is pretty impressive. Especially combined with what he did at Memphis.
But, again, this is just all my opinion.