Would be surprised if he makes it to Lincoln. Ou loses mixon and perine and he could start immediately. Ou system is easier to find the field early and often too.
Not that I disagree with you but Oklahoma does have 3 other 4 star RB's still on the roster. And a 4 star RB not on campus yet for 2017 and a 4 star athlete that is as big as their other RB's.
Looking at those guys (Anthony Sheppard, Abdul Adams, Kennedy Brooks, and Trey Sermon, maybe missed one?), they are all 4 stars, however Pledger is another level and borderline 5 star instead of a low end 4 star. Talent level is at an entirely different level and he should be able to compete right away. OU is also a more proven commodity in regards to producing running backs in recent years and having success on the field.
Plus I don't think he's a kid who is going to shy away from competition. In the end even if he commits, I think he still takes other visits, with us potentially still being one.