Heroes VII

Besides, it looks more like armor, even though, in theory, these knights are supposed to be fast units.

That doesn't contradict the other point; they supposedly appear from the grass and behind trees using magic. Poof-poof!

Also, the helmet and shield look ridiculous. And while the shield is somewhat acceptable, I've never understood the desire to give troops such absurd headgear.

Actually, decorating headgear and helmets is a rather old tradition. Hoplites decorated them with feathers, Vikings with horns, and people decorated them with all sorts of things... Look at the hats of modern British guards protecting Buckingham Palace. So, I don't see anything so terrible about these a-la wings. It's not practical, yes, but I can't say it's unrealistic.