There is no defensive skillset, only a handful of defensive skills in total through all of the skill pools, and only one not emphasized way to increase defenses outside of armor. What part of the game makes you think that they want "tanks" to be a viable option?
Edit
The emphasis is pretty clearly on executing a well planned strategy to take control of the battlefield. How you achieve that can vary, but that end result is what they have decided is what people should be aiming for. You're free to not be satisfied with that, but that's the way it is.
Last edited by Kilroy512512; 17/10/16 03:19 AM.