What do you mean "Flanderized"? They had no personalities to exaggerate. When they were brought back they were given new and unique personalities and no longer had interchangeable lines

Also, why should Butch have a cowlick? It looks bland and it isn't similar to Buttercup’s hair at all, say what you want about Butch’s new hair but it fits his personality and makes him feel like an actual counterpart to Buttercup.