Looking at Ole Miss, a bit below the numbers from footballoutsiders:
S&P+ -- (success and points) opponent adjusted measure of per-play success based on down and distance and on expected points from yardline. The "+" is a drive efficiency factor.
By this measure, their Defense is 21st against the run and 22nd against the pass. By comparison, Pitt is 20 against the run and 25 against the pass; BYU is 16 and 28. Compared to Pitt, Ole Miss has been more successful in keeping teams from scoring, 20th vs. 39th in Drive Efficiency. This difference is also reflected in DFEI, where Ole Miss is 25 and Pitt is 44. This difference may reflect Ole Miss having a better offense (OffS&P+ 48 vs 67) resulting in better field position (though I would think that was accounted for) and more turnovers gained (20 vs 16).
By this S&P+ measure, their Offense is 62nd rushing and 46th passing. By comparison, Miami is 8, BYU is 16, Georgie is 27 in Rushing S&P+ (Georgie's score includes the games when Gurley didn't play). Closer to Ole Miss' numbers are Duke at 42 and UNC at 73 in Rushing S&P+. When it comes to passing, Miami is 3, georgie is 4, Clemson is 9, UNC is 18, Duke is 34 and Pitt is 66.