There's pretty much no upside to Steele at all. The guy went 9-36 at Baylor and got fired at Clemson after his defense gave up the most points ever in a bowl game. If the fans thought Schiano was bad, I don't see how a guy like Steele is acceptable. And HC in waiting arrangements 9 times out of 10 end up not working out well either. If Steele doesn't work out, it's better if UT just starts fresh again with a coaching search instead of having to lock themselves into or having to buy out Martin on top of it.
I can't say Tucker seems all that great either, but at least there's upside with him. His NFL defenses may have been bad, but then again, he was coordinating for the Browns, Jaguars, and Bears, which may as well by the unholy trinity of poorly run NFL teams. His college career seems to at least be off to a good start, and he was getting head coaching interviews when he was in the NFL.
I can at least see some potential with Tucker, while there's next to zero with Steele.
Of course, Greg Schiano would be better than either, though.