With Tanking not being a LvLing art...
Who said? Make it so! Yeah, I know the arguments back and forth. I am
leveling as a Tank with 'Fynn. Of course, I also now have the experience, so it makes a difference. I do think and most might agree, that it is hard to level as a Tankadin the first time around simply because of the overwhelming amount of info/abilities/talents/responsibilities that one must keep track of.
Nevertheless, with some time and experience, I am convinced that one can level a Tankadin almost exclusively by instance, Tanking them, one and all! That does not mean you would necessarily want to... There are some GREAT rewards from quests that are better than dungeon drops, so... The key is to balance these things, get as much real tanking done while leveling, and target whatever Tank gear you need from quests, do those quests, and queue for instances in between.
And there's honestly no reason why a noob could not Tank from 20 on up, with decent advice, and a nice guide on the best way to get low level Tanking gear. We make things hard on ourselves.