I like that we're back hip deep into the 'canon' argument without anyone mentioning it. @Paul Farquhar - I agree, using one class to 'invalidate' another is indeed rubbish in game where the DM decides what to use. Also rubbish is the idea that the fluff is somehow inviolable and that changing it is tantamount to changing a rule (i.e. homebrew, used a pejorative). Both notions are complete bollocks - they are personal takes on how to play the game, not immutable rules of D&D. Feels are not facts.