OP, my kid didn’t go to Vassar, but his school also didn’t isolate freshmen in their own dorms. It worked out well – in fact his sophomore year, he entered the housing lottery with a senior. The older students gave a lot of helpful guidance. Also, post- grad, many of those older students have been helpful resources in working through career choices and exploring grad schools. He also has friends who graduated a year or two afterhim.
In a smaller school, it helps expand the friend choices from the 500 in your year to any of the 2000 on campus.