So the Crimson Slaughter rules say that Possessed in a Crimson Slaughter detachment are Troops. But all CSMs from all sources are part of the same faction, so aren't they all permitted in a single CAD for example?
Or to get Possessed as Troops (or Chosen with VOLTW from Black Legion) does the whole detachment have to follow and limit itself to things from the particular supplement? And if that is the case, can one take Crimson Slaughter as an Allied detachment to regular CSMs then? I thought that an Allied Detachment had to be a different faction than the Primary, which in this example is a CSM CAD. Hmmmmmm.....