Yeah, still not the question being asked. Though interesting to know.For that, you would effectively see a bonus to that roll. For example, if they were trying to disengage, then they would get a +15 (White Scars). In terms of the narrative, the White Scars would effectively be guiding the Wardens in an orderred retreat. Let me know if that doesn't answer the question.
Assuming Kesar was canon, and we were playing as Magnus. We've got a bunch of our sons working with Kesar, as say they take Velnias. What roll bonuses do we as Magnus see from Kesar's Legion, in a similar vain to how we as Kesar see the +20 Salamander bonus from our sons working with Vulkan.