This, also smoke less.
Dark Rangers are just hunter reskins, (no, conflating her borrowed jailer powers with dark ranger stuff does not make it unique) night wartior is nothing close to even a class concept, and shadow hunters are more a vague idea that partly overlaps with shamans.
That said faction-locked classes is a dumb idea from a gameplay point of view too, unless you intend to use this to force people to play alliance (which is still dumb, but which might work to restore some semblance of balance).