To be frank Chosen, Chaos knights and chaos warriors don't exist to the norsemen their just names that the weak bellied southmen have come up with. In a Chaos horde your power makes your rank so a mighty sorcerer or warrior will be higher in the command chain then Marauders if there would be such a thing in a army.
I think most armies are just made up of warriors following one chieftain or commander of their warband who would in turn follow a chaos lord, And a chaos lord could still be forced to follow a deamon prince who probebly follows his own agenda. There are special cases where a chaos lord could boss around a deamon prince but they are exceptions to teh rule like everchosen.
Check out my warriors of chaos log here