Take a look at the league brackets over a few years to get a sense of the schools’ level of competition.
My kids didn’t apply as athletic recruits so take this with a grain of salt, but if you’re looking for generous financial aid you might want to include in your search some schools with less elite teams but that have large per student endowments and financial aid budgets.
As someone above noted, East Coast boarding schools generally give out financial aid rather than merit aid. But the definition of “family financial need” will differ substantially from one school to another.