I always have found 6 character so much chaos and confusion and don't understand why people are nursing about rules that much. In my pretty party design, i ll create a frontline warrior paladinlike, a healer wizard enchanter or cleric, a rogue of course in different shapeways and a guy with very devourer destruction skills. But 4 character is very limited in a rpg fantasy world ı can see that. 5 is the best in my opinion, you can add whatever you want far from any limitation, and no such chaos as 6.