For years 1-2 all you need is a classroom, anatomy lab, and omm lab. As for being the biggest med. school, LECOM has 3 branches, thus they are all considered part of LECOM (Erie - 250, Seton Hill - 100, Bradeton - 150? - Total: ~500)
Also, when you drive by a medical school such as a big university hospital (Cleveland Clinic / Northwestern), the actual medical school is usually small (all your classes might be on 1 floor of building X), but it seems big as it has a huge hospital and research labs attached to it.
CCOM is spread out campus with different buildings for administration, registrar, library, gym, dorms and thus it has a more campus field. LECOM has a gym and hospital about a mile away from the school and all the other admin/library stuff are in the same main building.