The issue with Lane isn't whether he's a good offensive coach(He's a dynamite playcaller and QB coach), the question is can you win big with him, or will there always be a ceiling, due to his personal issues and lack of attention to detail in regards to program management. I don't think it's an accident that he failed at USC, and you can't blame the NCAA for everything that happened. I don't think he's nearly as strong of a recruiter as he could be, and that's because he likely believes that talent is secondary to what he puts on the blackboard. A lot of scheme proficient guys are that way, Lincoln Riley is a classic example of this mindset.
Lane has found his niche, a big fish in a small pond. He can and should be able to win 9-10 games per year at Ole Miss, with the occasional win over Georgia, Alabama, etc. I don't know if Ole Miss will ever get tired of being in the hunt, but not a power.