This is more of a cameo than a detail, but it’s real weird. One of the soldiers that meets Superman in Man of Steel is Aaron Smolinski, who actually played Superman.

Kind of. He played the toddler of Clark Kent back in 1978, and he was only two years old when he did it. This is the third Superman film he’s starred in to date (he also has an uncredited cameo in Superman III as a boy at a photo booth).