Kaerah don't like the desert very much (too little water for their tastes), but I have no problems with you bringing it there. It looks like the S'laaeth will say they have a right to a huge expansion for all that desert. I'll ally with the main enemies of the S'laaeth because the Kaerah will be against such powerful expansion...by someone else.
EDIT: Okay, Aqua. We'll listen to what you have to say. Mysterious Rook, you can capture the two budding "love birds" if you want, but I'm starting some character development on them so I'd ask that you don't kill them. You can pick off the other members if you want.