Ok Sts defense is better statistically.
Essentially they are tied but Clemson has a slight edge IMO due to the fact that they never fall out of the top 40 in any rating. Essentially even what they are "bad" at they are still in t he top third of collegeiate football teams. Okie State has two categories - three if you want to break down turnvoers into separate categories - where they are among the bottom in college football. Okie State has one of the absolute worst red zone defenses in the game coming in at 104th. Clemson's red zone defense is 2nd. That by far is the biggest and primary separator. Clemson has given up a few more yards, but they give up less points and take the ball away at a higher level while Okie State creates more TFL's and Sacks. Clemson also has a better passing effeciency defense - which is where Brock excels.
Essentially, there are areas where Oklahoma State is slightly better than Clemson, yes. The only difference between the two is that Clemson never drops out of the top 40 in anything - while Oklahome State is one of the weaker teams in terms of take aways and red zone defense not that Clemson is great at forcing turnovers.
Basically both are great defenses - its just Clemson has fewer "weaknesses" and that's probably the wrong term for Oklahoma State's defense. Clemson does everything well or in the upper third of college football teams where there are 2 or three areas that Okie State does not.
Red Zone Defense - Clemson #2, Oklahoma State #104th
Scoring Defense, Clemson #2 - Okie State #5
Fumbles Recovered - Clemson #32, Okie State # 69th
Passes Interception - Clemson #40, Okie State #86th
Team Passing Effeciency Defense - Clemson is ranked #6th, Okie State is 10th
Offensive touchdowns allowed - Clemson by 1
Total Touchdowns allowed - Clemson by 1
Yards Per Play - Clemson at 4.44 over Okie Stat at 4.46
Turnovers Gained - Clemson #37, Okie State #88th
Rush TD's Allowed - Clemson has given up 7, Oklahoma State 9
1st Downs Allowed Defense - Okie State #5th, Clemson #21st
3rd Down Percentage - Okie State 1st, Clemson #23rd
4th Down Percentage - Okie State 7th, Clemson #39th
Sacks - Okie State is 1st, Clemson is 5th
Tackles for Loss - Okie State is 1st, Clemson is 10th
Yards Per Game - Okie State gives up 281, Clemson 308
Total Defense - Okie State is #3, Clemson is #9
Rushing Defense - Okie State is #6, Clemson is #9
Yards Per Rush - Okie State 2.81, Clemson 2.83
Passing Defense - Okie State is 12th, Clemson is 36th
Passing TD's - Oklahoma State has allowed 9, Clemson has allowed 10
Essentially, both have been very good and elite defenses all season. Its splitting hairs for the most part with the exception that there is no category that Clemson falls out of the top 40. There are two that Oklahoma State does, with one being amongst the worst in all of college football shockingly in terms of red zone defense.
Basically its like playing Okie State but they give up fewer touchdowns overall and a lot less points in the red zone while taking the ball away slightly better while giving up a few more yards and first downs.
Again, it really is apples to apples. Not much separation. Clemson IMO is just a little bit better because of the scoring defense, red zone defense and an ability to take the ball away. But as always that is simply an opnion. Okie State's defense is certianly very very good and easily one of the better defenses in the country. They just are really bad in the red zone and at taking the ball away. Clemson doesn't have a category where they are really bad and that is way in a very close call, they are a half step better than Okie State