Well, Chaos is the one exception to the "more is better" mindset, but that is because we can get some of the hardest, most powerful combinations with all the armory and daemonic choices. With chaos you can have a super-man in every squad, so tooling them up isn't a bad choice. Unfortunately, the game is one of numbers, so most armies can do very well if they "horde" their numbers, especially Marines or Necrons. I guess to a lesser extent that Chaos also uses numbers, in the fact you can have 3 powerful models in an army with minimum choices.