Leach's offense will be baffling to the offensively conservative SEC. I initially thought he was heading to a program that couldn't get traction in a conference with Alabama and LSU, but then remembered that Mississippi State was ranked #1 a few years ago. My biggest concern is for Leach, and the lack of patience that Mississippi State has for their football coaches. This is like their 3rd head coach hire in the past 5 years.
To the first point, I think that offense will not be successful in the SEC before, it's not like it hasn't been tried before, it's not like he hasn't tried it before. SEC defenses are generally good because they have the best defensive talent. It's completely different than getting fat off of a mediocre Big 12, which that era was, and a historically awful Pac 12.
As to the second point, Mississippi State talent and how "close" they've been, I'll respond the same as I would those who are talking about how "close" Leach was at Washington State, once. It doesn't mean anything, anything at all. I'm being serious when I say this but in the BCS/CFP era, the only programs I can think of that weren't close in at least one season are Kentucky and Vandy. Think of all of the other worst programs of this era; KU, Rutgers, Illinois, Colorado, Wake, Georgia Tech, whomever they all had a close year. That's a crutch to dumb down accomplishments, neither Mississippi State nor Leach has shown any ability to sustain the type of success that would allow that hire to make sense.
