The other thing about rankings is the conferences the colleges are in, some of these conferences hold a lot more strong teams than others, but the rankings of those who don't hit top 4 get pushed down, but many would actually be stronger than some who finish top 4 in lesser conferences. Their are also other things to consider, the coaching staff can also be a big factor in choice, the uni courses offered, the location, the position they play and how many are likely to be before them on the roster. Also the strength of the team mates that they will have to train against. It's not like here where these players can go train with older bigger bodied and more experienced women who play in WNBL and seabl. They are only permitted to train against other college athletes max age 23, who have never played against nor with any senior players. This is why colleges like the Aussie kids who have had exposure to these stronger trainings and game play.
How many times do you see athletes go to colleges that are so called top ranked only to sit there for the first couple of years sometimes more.
Also a lot of these colleges fly on the coat tails of the men's programs, st Mary's is one that comes to mind.