Golden Age comics have strengths and faults in many areas. They have fast, simple stories and bizarre weirdness, but they also have rampant racism and often forgettable and interchangeable villains.
That's probably why I like Air Fighters comics-they manage to dodge this last one to no small degree.
Those are, respectively from top left to bottom right (in "English reading" order): A spy pretending to be a Nazi ghost; a "half-man" Nazi cyborg (they apparently hadn't invented the word cyborg yet), a generic tough Nazi who got a tattoo, and a Nazi with a mechanically enhanced mask covering his mutilated face who has superhuman vision.
Okay, well, yeah, obviously they're all Nazis. But at least they aren't all easily swapped with each other seamlessly like most Golden Age villains, right? (Air Fighters' "sister title" Clue Comics featured about one truly memorable villain, the Crane, who had extending arms... and was a Nazi spy. Hm, there's a definite pattern.)