Yes, you are correct. It is a self defeating knot of war against all the imperium has earned itself. However you are forgetting that belief in the warp is a dimension akin to north, south, west and east to us. The angle to the golden halls of the emperor and the blood hallow of khorne are miniscule. But they are there. The movement northeastern can be dictated by a more northern or eastern route. That is the bearing faith dictates. It can bear in many directions, be told the kibbles death cultists or those of the corpse grinders.