Oregon had several dumb turnovers against LSU. LSU won and were the better team but let's not pretend that LSU D was the 2000 Baltimore Ravens or 1985 Bears.
Texas is 54th after playing the following offenses and defensing them better than pretty much anyone
OSU (better than WVU by far. Remember WVU was in their first month of live action in the Air Raid after being a run-first team for several years and still hung 500 on LSU)
Baylor (#2 in the nation)
A&M (Hung 600+ on you)
Mizzou (Arkansas fans should remember Mizzou's offense after the 2008 Cotton Bowl)
OU (Got them before injuries depleted their offense)
Tech (Did as well or better offensively than Arkansas with 3 common foes (KSU, ATM, UNM))
Against teams with similar offenses to what the non-Arky SEC teams have... UT gave up much less. UCLA, Cal, BYU, KSU, and ISU are very similar to Bama's foes other than arkansas offensively and UT gave up a meager 249 ypg and 15 ppg. This average drops to 216 and 12 with KU and Rice added in. UT's defense is only ranked low as a result of having to face elite offenses for almost half the schedule. Even still they shut down MU and A&M as well as doing well per play against TT when backups gave up some late yards.
Make LSU play 4 more offenses like Oregon and WVU instead of WKU, Ole Miss, MSU, and UK. I think the averages would be very similar. Auburn's offense does not count... they are average at best and so is the UGA offense that struggled against a BSU team that TCU torched with a freshman QB.
Texas, Bama, and LSU are 3 elite defenses this year. Unfortunately UT is the only one who had to face more than 3 top flight offenses. Bama only had to face Arky! LSU at least faced WVU and Oregon.