There are several companies making building "pods" that consist of kitchen and bathroom fixtures. Pre-plumbes and with electric circuits.
In some areas there is a building type "K" or "K Class" that allows marginal improvements and occupancy before final.
I've seen a "Pod" used with 4 storage containers in a pinwheel pattern with the pod located in the center.
Two storage containers can also be places parallel to each other 10' or more apart and trusses installed over the entire "building, or truss the gap and construct shed rook over the two containers.
Make sure to provide ancors to foundation for the containers, slab in between, and I beams wherever you cut out the storage container sidewalls.