Back from the holiday :)
"Zul'Jin a know. We a go now, be a back soon."
So my plan is to not really go raid, Caliban gave enough info about meeting the leaders that we can report back, possible have a golden tree idol decoy mocked up and the horde send a brute squad in to kill/take any of the leaders. Even if they were planning an attack on the horde they may not admit it but cutting off their head will should make them easier to eliminate. After leaving Caliban Zul'Jin will go run this by the warchief they took the job from and see if they agree. He will report the elven camp and that they should crush it and take the tree anyway for the horde :)