How important ranking is to acceptances depends very much on how schools do ranking. Just as an example a school that doesn’t have any kids of weighting for more rigorous courses will have a less useful ranking except for colleges that accept strictly on ranking without making any judgment calls.
When I think of gaming the system, I think of kids who take courses in the summer, or at community colleges, or who take study halls instead of courses that are unweighted (in our system all the art courses). Luckily in our school there is a special diploma for art courses, and they are very popular even with the kids taking lots of APs. I haven’t seen anyone try to up their rank by not taking extra art courses.
My sister in law is still peeved that the valedictorian in her class as the same grades and took the same classes she did, but she also took orchestra on top of the full schedule - and was therefore downgraded. (She was salutatorian and got into Harvard so it obviously didn’t hurt her, I believe the val did very well too.)