Elemental Shaman Verses Rouges / Demon Hunters

I am sure the team at blizzard has put lots of thought into the various classes and as a new player (only been playing 4 months)I don’t really want to complain as I am sure I simply don’t understand the inherent balance in the game between the classes. And yet as an elemental shaman it is hard to imagine a scenario where a win condition can present itself against Demon Hunters / Rouges who have average skill level. When you are constantly stunned I can’t even call astral shift during those windows. I would realize that my skill level plays a huge role in all of this however there seems to be an imbalance when a certain class has access to many stuns and still does massive damage.

Can any experienced players who are successful in PVP comment on this or is it the intent of the devs that there will be massive disadvantages going against certain classes?