Emory and Vassar are strikingly different experiences- have you been to both? If not, if at all possible, get there. The feel is so very different, and we don’t know which will feel happier to you- which will matter more than any differences between the ‘opportunities’- you will do best in the place that suits you.
Not sure why you think that Emory is more science oriented or would have better science opportunities if Vassar’s acceptance rate is 50% higher than Emory’s, but the bigger piece is really fit.