Well, if they're going after one another, might as well double team 'em.
Maybe also make some... offerings to the Prince of Excess, hir loves Eldar.
yeah, the sacrifices are already part of the voting options and is separate on the actual battle plan...
[X] Yes, a special gift sounds great. (Will please Nurgle)
[X] Beseech one of the gods to intervene and save the dying Battle Brothers
-[X] The God-Emperor
--[X] Sacrifice some of the Eldar in His name.
[x] Battle Plan: For the Plague Lord!
-[x] interrogate the surviving eldar for any information (other camps, ships, their archons and kabals? how did they get here in the first place?) before sacrificing them.
-[x] Sacrifice some of the DE to Slaanesh to placate him and to earn his favor in fighting the DE.
-[x] Praise the gods and make a speech congratulating your battle-brothers for their faith, skill, and courage.
-[x] make sure that Brother Paul has all the resources he needs to ensure the safety of the Progenoid Glands of our fallen battle-brothers. (in case the god-emperor saw them worthy enough to serve him in the afterlife. in other words, if beseeching the god-emperor fails, the glands would be in safe hands.)
-[x] tell Ghost to make sure both DE footsoldier camps are too busy fighting each other to wonder about what's happening with the other camps (he can do this by assassinating scouts, killing a few DE if the fighting starts to die down or sabotaging communication nodes, or whatever, he's the expert). He should make sure that no DE survivors from the other camps warn the DE at the makeshift arena.
-[x] Another Champion of Nurgle interests you by the fact that he is interested in the God-Emperor, find out why. If he is also that concerned about the fate of the ordinary mortals, have him become your liaison regarding the affairs of the cultist and slaves, though he shouldn't spread the gift of the plague lord, we might need this mortals healthy.
-[x] Prepare the re-education of the slaves about the true gods. find out if any of them have useful skills and knowledge (officers? engineseers? sororitas?). If they 'disrespect' the gods though, well, its time to show them why you have the moniker of Tyrant!
-[x] your heavy troops as well as the other vehicles other than the predator tanks (i.e. the terminators,land raider) and the greater number of marines, lead by you Lord Caspian, should engage the DE at their vehicle camp. capture their vehicles whenever possible, but don't hesitate to destroy them either.
-[x] Send greetings and salutations to our new nurglite allies (via ritual) and ask about their situation. After that, our forces attacking the medical camp shall be lead by Brother Mortimer (hopefully wearing terminator armor won't hinder him much), along with sorcerer Damian, 10 champions (those not wearing terminator armor), a number battle-brothers that Mortimer thinks he might need, as well as the faster troops (i.e. raptors and rhinos) overwhelming the camp's defenders as quickly as posssible. Ask our nurglite sorcerer if Father Nurgle won't mind if we can have a couple of the Homonculi as playthings after the battle, if not then its no big deal (hopefully, the death guard won't backstab us... we will backstab them first though if its the Will of Tzeench)
-[x] The slave camp should be fortified and prepared for a counter-attack. Also have our two remaining sorcerers as well as the necessary number of marines (maybe 100?), the predator tanks, and the cultists be our reserve force to reinforce one of the attacks or both. Always check-in on our main base and make sure that nothing untoward is happening over there.
edited: moved sacrifice to Slaanesh into the Battle Plan.
@Night_stalker you're right, its should be included in the battle plan.