While Space Ghost mixed superhero tropes with sci-fi adventure, the other classic Hanna-Barbera "superhero" show, Birdman and the Galaxy Trio, barely has any superhero tropes at all. Sure, Birdman is technically a superhero in that he has a superpowers, wears a mask, and his name is Birdman, but he doesn't take his mask off, hide his wings, and go work in an office. He doesn't have a girlfriend from whom he has to hide his superheroic activities. Instead, he seems to live full-time in a volcano base, where his only friends are his falcon Avenger and later his sidekick Birdboy. He doesn't patrol a city to find crimes to stop, he just gets sent on missions by Falcon 7, on behalf of Inter-Nation Security.
The Galaxy Trio are pretty much the same, but in an outer space setting. At first glance they look like a superhero team, but in fact they're just one division of an interstellar law enforcement agency known as the Galactic Patrol. They don't even necessarily have superpowers, just alien abilities that humans lack. Like Birdman, they take their missions from a commanding officer, who they call chief. Birdman may not be much of a superhero, but the Galaxy Trio aren't superheroes at all—they're cops.