My concept, was to build around the ideas presented in each short fluff a character class. Paladin is for instance looked at as the holy warrior, but then you have cleric, Favored Soul, crusader, Soulborn, and that psionics dude no one talks about. Giving each class their space, then building each class within that space to the achievement of the concept.
I think a duality of all the classes would be a bit limiting, and also not a preferable design decision: Wizards (Hard Work) are opposite Warlocks (buy a thesis), while sorcerers and favored souls are opposite themselves (sorcerers look on their power as a curse, gift, or tool).
Cleric and Wizard were replaced on my concept list not because they are bad in and of themselves, but because one is OP no matter what, and the other uses a mobile mountain to crush paladin's space into non-existance