If Butch was at Miss St for as long as Mullen was, there would have been about 5 years where he went 3-9 (0-8). Mullen is 50 times the tactician Butch is.
Mullen didn't have talented teams at Miss St. He did not target highly-touted recruits there because he wouldn't have landed them even if he did. He was better off spending his time recruiting guys he had a better chance of landing. However, it is something to consider given he's now at a big job that expects to win titles and recruit at a very high level. It is still unclear if Mullen can recruit at a high level. The early returns haven't been impressive, and if he is to get Florida where the admin and fans want to go he's going to have to recruit top players.
If you want to win the SEC you have to obtain elite (or at least very good) talent and coach it up. There's no question he's a good talent developer/identifier (especially with lightly-recruited guys overlooked by major programs), and offensive schemer. I don't know if he simply doesn't want to recruit top talent or if he's incapable of recruiting top talent. If it is the latter, that's a huge problem for Florida. And if he can't recruit at Florida, he'd have a much worse time at Tennessee. That was the risk with him, because at his previous job he couldn't recruit at a top level even if he was attempting to. It's unknown. It is the MO of some coaches/programs to focus more on lightly-recruited guys and coach them up. It even works at places like Wisconsin and Michigan St, but those schools employ that strategy because there are extenuating circumstances that Florida doesn't have to deal with. Would such an approach work at Florida? I really don't think so.