Or do they have one large admissions committee that keeps in mind the differences in each school?
Each school sends at least one representative to the committee.
There’s one set of admissions officers and people rotate between reading apps for each school depending on the cycle. When final decisions are made, they’re made as one committee with officers who have read apps from each of the undergraduate programs. In the end they’re building one entering class that will be divided among the four schools as opposed to four separate classes. Hope that helps.