So when you look at school rankings, I assume those are usually focused on the overall mean student. But what about when you have a kid that is a on the outer edges of the bell curve?
Would you rather your kid go to a smaller 3-4A high school that is overall more highly ranked, but may not have some of the course/club options of a bigger 7a school. If the kid is a high achiever, do they have a better chance pushing themselves further at the school with more offerings and potentially more students in his/her ability level, or is there a reason they might benefit more from the being the "big fish" in a smaller pond scenario?
I guess same applies with sports... Would you rather the kid be a shoe in to be a star at a smaller school, or go compete to try become a star at the bigger school?
I'll give you my perspective as someone who's worked with undergrads and grad students for 3 decades now.
There's been some big changes in the last decade in the way kids get into med school, so if that's something your kid is considering, here's what's happened:
MCAT changed big-time about 10 years ago, primarily by adding additional sections dealing with social/behavioral sciences. What that means from a practical perspective is undergrads need additional courses above and beyond the old sequence of chem/organic/micro, etc. Now they really need sensation and perception/cog psych, wouldn't hurt to have A&P, physics I&II, biochem, Cal, regression, a neuroscience course wouldn't hurt either. From a practical perspective, the current prereqs are almost impossible to complete in a 4-year span, particularly if the college has a large core sequence.
However, If I get a kid who's been able to rack up college credits in high school through AP or dual enrollment, they have a huge advantage in finishing in a 4-year time frame. They'll also more likely to have taken several years of language, so I can test them out of the language requirement (8 hours more to play with) and they'll more than likely have pre-cal as well. And instead of taking summer courses to keep pace, that kid is going to have the time to do a few internships their junior and senior year which has become almost a necessity for getting in from an undergrad program.
Much the same is going to apply to kids that are looking at other professional schools or competitive grad programs. Coming in with hours in the bank already gives me as their advisor the flexibility to put them on internships, add a minor or an additional major, send them abroad for a semester, etc. All of that makes them more competitive for the next level of education.
So I would look less at the size of the school and more at the availability of advanced courses that your kid could benefit from. Even small schools may offer dual enrollment if there's a community college or university nearby (About 1/3 of my freshman class last semester where kids from the high school in town).