So these are a different kind of dragons then? So cliffracers wouldn't be any good.
Well, I mean, besides the fact that I'm pretty sure some guy from Morrowind killed off all of the cliffracers and was named a saint for it, it'd be worth a try I guess if you could find enough of the buggers.
But yes, these dragons are different in a sense. Not much is known about them, as we'll probably do most of the learning in the main quest, but these dragons answer to Alduin. They do still have free will, and so a few may be friendly or at the vary least neutral to you, but most will likely follow their boss' orders. Kinda like out the humanoid daedra we encountered in Oblivion had a mind of their own and free will to an extent, except the dragons are a lot more dangerous cause they're...well, dragons.