There is definitely overlap with candidates applying to both top universities and top liberal arts colleges. Size is not the main desired trait for everybody, though it is for some. And even those who prefer one size to another may have other factors that are important to them in a college that lead them to apply to colleges of varying sizes.
Son definitely preferred LAC’s overall, but had he not been accepted to Williams ED, the 20 colleges to which he would have applied would have included 6 colleges from the US News national university list, 13 colleges from the US News national liberal arts college list, and 1 mid-sized school from a US News regional list. And he had visited two additional national universities that did not make his final list.
It also seems, from admitted student group chats, posters’ comments on this site in threads and in PMs, web sites that compare which percentage of cross-admits went to which of two schools, etc., that the applicants who are accepted to Williams regular decision and turn it down are most often headed to Harvard, Princeton or Yale. It is less common to hear of someone picking somewhere else, whether large or small, above Williams, although it does happen. Maybe the students picking H, Y or P decide they prefer a larger college, but they may decide based on various other factors… and one of the biggest factors may be picking the most prestigious college to which they are accepted.
This is typical:
There was a thread here in one of the last couple of years about a kid who loved Bowdoin agonizing about a choice between Bowdoin, his or her stated “dream college,” and Princeton. The student ultimately chose Princeton.