Your argument is that orbital assembly didn't exist in the Apollo era, when Orbital Assembly WAS the runner up to the SaturnV single launch option [Source Original Posters Article].
This means logically some times its more cost efficient, or simpler to put 27 tons in orbit in one launch, then assembly 6 5 ton launches.
This means logically some times its more cost efficient, or simpler to put 27 tons in orbit in one launch, then assembly 6 5 ton launches.