The SEC has gone after a mixture of programs. Missouri is not there because of football for instance. UNC and Virginia are the only flagship Southern universities not in the SEC, and UNC at least have already established natural rivalries with Kentucky, South Carolina, and (to a lesser extent) Tennessee.I agree on SEC getting their choice.
The issue with UNC and UVA is that they aren’t football schools in the SEC mold.
If you look at who SEC has added, they’ve been very selective in going after football schools in a geographic region.