They're stereotypical indeed for the most part, put the way they are presented is superb. Ladd is made into an awesome character, which many people liked because he's amusing and quirky, as well as the fact he fights one guy even more crazy than him instead of some good guys. Add nice details to him lika masochistic Lua and you get very likeable character.
Same applies to others. Even Firo (worst case, in my opinion), is kinda cool because his perfectness is stylish.