Azax is not concerned enough about the orcs to want to intervene. Besides, thye can only lead us to the fortress if they don't know we are following. Plus, I would still like to get that dragon-riders sword away from them. And a bunch of dead orcs would just hand it over once the wyverling is done. Finally, I have a sneaky suspicion that our tail just might be the missing dragon rider. No proof, of course, just a hunch. But I'm inclined to say something like "Let the wyverling kill the orcs so we can claim that sword. if we can find the rider it can be restored to its rightful owner." If it is who I think it is, and they are close enough to hear us without alerting the wyverling, we may gain a friend. And if it is the rider, they almost certainly have useful information. So I say sit back and watch while making a brief comment we hope is overheard.