Basically.
Its what i loved about JLA/Avengers. Busiek went beyond slug fests and delved into how the two 'verses are different, how the same positions are there, but different.
Its why Supes and Cap were so heavily affected by the merging...
And why the two come to the forefront, in universe, and in threads like these...
Cap IS the Superman.
Superman IS the Cap.
In one universe though, the heart/inspiration/leadership etc. AND power are in one package, in the other, two characters fill the role...