The techniques used are completely different from anime produced around the same time. While some techniques overlap (poor translation of comic to cartoon with little interest for how scenes are moving), shows like Lupin III relied on a rule of threes for animation. Keyframes were exclusively redrawn for Japanese cartoons based on comics, whereas the particular style Captain America is aiming for is a direct translation of the comics. That’s why most of the animations are motion tweens or idle stuff–because it’s a voiced comic, as opposed to basically every other type of animation. By the way, it’s definitely a legit school of animation. You can see these techniques passed down to shows even today.