Radio Psychedelica

Both Doc Savage and Clark Kent had a 'Fortress of Solitude' in the far north which contained laboratories. Both of them would retire there for research and relaxation.
Co-incidence? Unlikely.
Doc Savage disappears shortly after the Second World War; no one knows if he died or retired.
Philip Jose Farmer suggests that Doc was growing increasingly frustrated as the years go by; certainly between the Nazi Horrors, and the growing Cold War he would have been justified in feeling that evildoers were winning. Certainly his idealistic patriotism would have been shaken - if not shattered - by Nagasaki and Hiroshima detonations.
He would also probably known of the 'hellish' deals made to trade pardons for data with Japanese scientists guilty of vivisection and torture; the whitewashing done to certain German rocket scientists, and of course, the growing truth of what our erstwhile ally Stalin had done - a monster whose 'labour camps' dwarfed Hitler's Die Endlösung der Judenfrage .
What would have remained of his belief in a shining future?

My father suggests that Clark Kent killed Clark Savage Jr., and took his laboratory; this certainly would have given Superman acsess to Savage's stockpile of captured and invented weapons, which would have given him a huge advantage in his struggles.
I think however, the similarity in their names goes farther than co-incidence.
I suggest that Clark "Doc" Savage Jr. created Superman.
The Man of Bronze creates the Man of Steel; harder, faster and certainly better suited for 'rough and tumble' work.

After all, the cover story of 'being from the shattered planet Krypton' is quite fantastic, but would allow Superman the cachet of being 'alien' and hence 'non-partisan' -- a non-partisan alien who spends his time defending the American way.
What are the odds that a highly advanced alien would find the U.S. the most appealing socially?
At that time (late 1940's, early 1950's) that nation was racially segregated, increasingly paranoid
and the wielder of atomic weapons.
I suspect that Doc felt he was a defender of his nation and could'nt leave his battlefield. I also suspect he created Superman as a 'fire and forget' weapon; indestructible, intelligent, pure of heart and deed; a steel dynamo who would never suffer as Doc had suffered; that would never know loss, or greif or doubt.