Yeah but Carter seems more believable given that real folks are able to do things in a lower G enviroment than they can normally. Burroughs claimed that Martian gravity was less than Earth’s making Carter stronger than the Martians. And Mars does have less gravity than Earth. Agility, though, I’m not sure he’d be more agile in a lower gravity enviroment. But you wouldn’t get heat vision, x-ray vision, super breath, the ability to fly (you’d be more like Hulk in that you could make more super jumps but that isn’t true flight), and so many other powers Superman gains from a yellow sun.