Surely, Kal's advantages would be much watered-down on Mars as opposed to Earth where he'd clearly be superior.
Whoa. What an interesting idea. Jor-El deliberately choosing Earth over Mars precisely because he wanted Kal-El to be the physical superior of those around him.
But on Mars, Kal-El would have been more at home, I think. He would have been raised by people with powers much like his own. He might have even learned more powers than he could on Earth.