I think everything could work if they separated the EX/SAVAGE content (the content that actually revolves around balance and homogenized/scripted gameplay) Vs Casual play, normal raids, and DNGS (places that can afford a little diversity and leniency in terms of gameplay mechanics.

SE separated PVP and PVE -- PVP has what is basically a different skill hotbar for every class, and even a few spells that the classes themselves don't have for PVE. Why cant they do the same For Casual vs Competitive play by separating Casual vs Competitive classes and abilities so everyone has fun.

If they did this they wouldn't have to worry about having coded themselves into a Balance-box with Casual content and they would now just be able to make separate class mechanics and spells that don't need to take into account for perfect numbers or savage content, but those who like the competitive edge in raids wont have to loose out on anything either since their balanced class mechanics would essentially be separated and untouched.