Vandy normally gets beaten, blown out in some cases, by those teams that they've beaten. I know South Carolina, LSU, and Auburn have issues, but those rosters are still infinitely more talented than Vandy. They also held their own against Texas in Austin, again against an infinitely more talented roster. A "typical" Vandy team probably still beats South Carolina this year but loses to LSU, Mizzou, and Auburn. They'd be 6-6 right now.
Pavia is undoubtedly the straw that stirs their drink, and I'm curious to see if Lea can keep their good run of play going after he leaves. But saying "he isn't a good coach - he hired a guy who brought in a really good player" is a non sequitur. Hiring good staff members is a huge part of any HC's job.