I would choose Stallone for the reason you gave....he was not only an actor, but a writer and producer that developed legendary characters from nothing.
Stallone gave us more than just a performance....which is all Arnold provided.
I wanna nominate the guy who does their special effects.
You certainly are right there. Never forget, Stallone WROTE Rocky and the only reason he became a known actor was because he starved rather than sell the screenplay without being named to play Rocky.