OU, TX, TAM, LSU are all recruiting from the same base.
So the 4 and 5* athletes going to one or the other just comes down to personal preference of the individual kids. They don't become speedier, stronger, more driven, or whatnot just by getting picked up by Texas A&M or LSU instead of Texas or Oklahoma.
The bigger unknown is if COACHING is up to the challenge. Based on recent history I'd say yes for Oklahoma, no for Texas.