What NPCs would you like to see? For example: Ahriman or some other powerful chaos lord/chapter master.
I think there should be a min number of ork boyz on the map and if players can't fill it npc start to do it.
Hmm! Actually... there will be some important NPCs communicating with the factions. They won't be "quest givers" or anything like that, but... you'll see some, dare I say, familiar faces? We hope so, anyway.
You guys should plop Khorne down in the middle of the planet and have him yell "NEED MORE BLOOD FOR KHORNE FLAKES".
I don't mind NPC's being in the game at certain positions to provide some communication or protection of fortresses to provide some defense against assaults in the dead of night. However that's all they should be, just a small buffer to provide a warning for players that a fortress is under attack and the like.
Character NPCs will tie into the setting of Objectives during Campaigns, but these will probably be very distant from the conflict. We're considering some 'buffer npcs' to protect fortresses from surprise attacks, as you mention, but we agree with you- this conflict is focused on the players.
Are you guys planning on showing the character NPCs or letting them have a presence in the game besides just communication?
It makes sense. If I'm fighting over a planet, it's probably because Azrael is giving the order to. I'd fully expect some sort of contact with Chapter Masters/Phoenix Lords/Dark Gods to occur.
considering that 4 chapters have forces on the planet one would assume that a chapter master was in charge... which would also make this a major conflict...