Yeah, the Clark is real idea leans heavily on him being an orphan, an alien, and different more so than "I'm like everyone else". It's become one of the major themes of Superman now that Clark will accept he's an alien or struggle to understand his powers and/or what he should do.
I might be reading this wrong, but Siegel would've never had Clark grow up a normal American. Originally, it was Jonathan Kent who told Clark to hide his powers,
Superman #1 (1939). In
More Fun Time #101, Clark frightened two young boys when he lifted up the car saving the man from dying under it. In all of the early origins (1938-1939), Clark had always scared the orphanage works with his display of strength.
https://thoughtsandramblingsofhardwi...tons-superman/ here's an example of Siegel's original intentions. We just got glimpses of what could've been. I found the article the abandoned Siegel-Keaton Superman, while looking for another letter written by Siegel. This origin is similar to what had gotten published in the Newspaper Strips. Let's not forget,
Gladiator was a big influence on Superman, and that novel was about a man trying to hide hid awesome strength and speed to blind in with others.
It's interesting, the discussion about who is "real" between Superman and Clark Kent, when S & S had laid down the idea very clearly in the comics (books and newspapers). They're one and the same. There shouldn't be a delineation between the two.