We rotate 3 complete lines (Johnson, Nkemdiche, Hamilton, Brown, then Haynes, Gross, Bennett, Ward, then Youngblood, Hooks, Martin, and Thompson, though the rotations may vary.) Our LB spots are 2 deep with the 3rd guy playing 3rd for both spots. (Bryant, Nkemdiche at Stinger, Shackleford, Russell at MLB, and SR Keith Lewis plays both) Our secondary is missing 3 players (1 starter) already and is still considered by some to be the best in the conference.
It's by far the deepest defense Ole Miss has had since the '60's and it is showing. The defense has given up just 6 touchdowns through 6 games, and two of those were garbage time against A&M. Opponents tend to drive occasionally but their drives just seem to die outside of field goal range and throwing into the end zone has just been a no-no. We don't get a lot of sacks so some perceive us as having a weak pass rush, but that's inaccurate I think. We have gotten away with rushing 3 or 4 most of the year and get just enough pressure to force errant decisions, resulting in low completion percentages and high interception volume.
I think Ole Miss has a better overall defense right now. MSU probably has the 2nd best in the conference right now though. Both are probably top 10 nationally.