Whatever Stanford’s recruiting polices are, they seem to be working well from an academic success standpoint. Stanford athletes have the highest FR grad among all div I colleges for which this figure is reported, by a good margin. Stanford athletes are among the top on GSR grad rate as well, meeting or exceeding the grad rate at all ivies except Dartmouth. Two of the four most popular majors among Stanford athletes are in engineering, and a notable portion of athletes later attend med school. I expect that Stanford athletic recruits are restricted to students who Stanford expects can handle the coursework and succeed academically, as determined by a variety of criteria within their application, rather than just test score, GPA, or other stats.
In sports where athletes have little chance or professionally playing the sport after college, a good portion of the top ranked HS athletes usually meet this criteria, and such student athletes are often interested in attending schools like Stanford. However, recruiting for sports like football poses more of a challenge. Even if you do have some top football recruits who are stellar students, they often favor colleges that they believe will give them the best chance of making it to the NFL, rather than top USNWR type colleges.