It seems like this conversation is missing the key point that an engine house is primarily for maintenance, not for storing engines.
A one horse short line might have a one stall engine house if in an area of cold winters. Storing the engine when not being maintained would make sense as an efficient use of track length.
On a railroad with many engines, most would be on outside ready tracks and those few needing maintenance in the house.
A three engine short line would make do with a one stall engine house.
Even financially precarious short line had turntables. Otherwise a wye would be needed and that requires a lot more land and wouldn't work along a river in a narrow valley.
