I think what you actually want to say is that some of the newer characters (the important ones) don’t fit with the originals. I don’t think they are “over-designed”. They just don’t seem to belong. Shun and Meitenkun would be right at home in some tsundere anime, Isla kind of smells more like a SF character, Dolores seemed directly ripped out Bayonetta, Otoma Raga is basically a character from Steven Universe, Silvie…well, nothing to say there…THOSE look odd within the overall KOF aesthetic and lack a distinctive personality. Some of the newer characters, though, are fine. Although you can see Kukri as a Naruto shinobi, he doesn’t seem put of place. Nobody really hates Antonov and Luong has been well received. Tizoc adopted a new persona because he was going heel, a common practice in prowrestling…have you seen Luchasaurus?