However I think being opposites they are the same, think if them like crystal=1 & Dark = -1 they are both ones but -one is negative & one is positive, however this may confuse some ppl...
Well, I think that they are grouped that way because it makes people play a more verity of magic because if opposites were not grouped, there would be lots of the same mages like ones that only fallow charisma or only wisdom etc. it sort of negates the 6 different types & makes it only 3....
?(