I did mention that with the "perpetual turf wars". I mean, if they're really that belligerent, sure, they could go looking for allies, but at that point, would the Alliance really want them? That kind of racial personality doesn't seem like something the Alliance would want to put up with. That's why Jaina and Greymane stand out like a sore thumb. As Alliance players like to point out, the Alliance are the stereotypical "good guys". A race of snake people who want war over peace wouldn't sit well in the Alliance. And if they want peace over war, then joining the Horde is the best way to get it for their section of the world.