Advantages?
" The twin fuselage configuration offers the advantage of a clean payload area underneath the wing centre section."
I count about 30+ aircraft (most military) that have been twin fuselage.
"During World War II a need sometimes also arose for a heavy fighter, which could not be met by a new design in the time needed. Joining two examples of an existing lighter aircraft was one way to achieve this."
See also what are the advantages of twin-fuselage aircraft?
The first seems to have been around 1915. Most didn't meet expectations of performance. There would probably be no advantage in having more than two fuselages.
I think the single fuselage approach might end up like this family:
Still looks like SF 60 years later. Came in different sizes.
Biting the hand that feeds IT
