I previously asked a question (Grounding subpanels located ~100ft from main breaker) where I was informed of NEC 225.30, which states that a building
[...] shall be supplied by only one feeder or branch circuit [...]
It sounds like this code exists to ensure that each building has a single breaker or disconnect method that disconnects the entire building.
How does this relate to a building which has a main breaker panel that feeds multiple subpanels? For example, if I have a 200A main panel with two 100A breakers, each feeding a 125A subpanel (with no main breaker, only branch circuit breakers), do the main panel and subpanels all need to be on the same building, or can the main breaker panel be located close to the meter (on a separate building) with the subpanels on a different building?
Functionally, there is no difference between the two setups, except physical location of the panels. In both cases, there is a single breaker that will disconnect both subpanels.