I guess the best way to put this is ...
Pinewood has a handful of kids who would play significant roles and/or start for most (if not all) public schools in the state. Realistically, that quality does not spread throughout the entire roster, or even the starting lineup. Still, Pinewood is capable of beating a lot of programs.
My guess is, you can say the same of Cardinal Newman.
Now, I don't necessarily buy into the type of ranking posted above. But if I did, I'd say that a #24 ranking would seem to imply that SOMEBODY thinks Hammond is among the upper third of all SC High School programs, regardless of enrollment.