My daughter has a few Singapore friends (from SAS) who barely lasted freshman year at Skidmore and Syracuse respectively as they felt it was the schools were either too isolated, too far from major cities, diversity was there but not enough for them in school; you want a school with large-ish international community as much as “diversity”
of the unhappy freshman mentioned above - 1 transferred to school in boston and 1 to a school in DC and are infinitely times happier in these new environments
of your 2 choices - vassar seems better located (NYC) to achieve comfort in what a big city has to offer.