I went to a model railroad convention here in Seattle many years ago. The literal engineering that went into the production was uber phenomenal.
What they do is specify an entry table size and interface dimensions, track locations for the interface, etc. That way all compatible entries will interface (edge up properly/interoperate) with the next entry. Thus you can have a 1880's diorama interface with a 1950's scenario with a 1941 WW2 railyard with a Canadian Rockies Express.
It is rather phenomenal how these guys put all these entries together and then set up an engineer's station to run all the trains. It is something similar to air traffic control, but with all the electrical, mechanical and physical interface implications. Impressive as hell actually.