In this universe, what makes Superman special is the fact that he is the only normal born Kryptonian. Every other Kryptonian was genetically altered to be gifted in one specific aspect that would allow them to do a specific task when they are old enough, like a child that is changed to be stronger so he can grow up to be a construction worker or something. This probably translates to why Superman can fight equally with an army of super-powered Kryptonians, because if this was the comics, then they would be just as strong, fast, etc., as him (although he'll probably beat them thanks to his experience, which he doesn't have here). But in this movie, some have hypothesized that since Kal-El was born normally, he would have a full set of powers, while the others would only have one power each, but that power is better than Kal-El's (like Zod having a flamethrower-esque heat vision compared to Kal-El's beam-like heat vision. I'd imagine that another example would be one Kryptonian would have superior strength to Superman, but he wouldn't have any other powers, unlike Superman.). P.S. I don't know why I was using Kal-El for most of that, and then randomly switched to Superman... It just happened.