Ah, a fan of Mr. Witcomb I see, ;-) are you aware of the "poor man's area rule" via John Thorp? Google: adverse pressure gradient matching ar-5 to find the link...
The "poor man's area rule" deals with interference drag, which is a different form of drag that includes subsonic performance. It too has an effect on aircraft shape and accounts for some odd and inventive if ugly aircraft designs.
Notably, Richard Whitcomb's insight into the area rule principle was anticipated by German work in the closing years of WW II. Mercifully, the war ended before it could be incorporated into Nazi Germany's jet aircraft.