[Drax]

neither the Company of Misery of the Steel Brethren ring any bells with me so i cannot really cast a fair vote

however i would say go with your own scheme - that way you can freely choose your codex without some jobsworth saying they aren't chaosy enough to use chaos or they are too chaosy to use loyalist.

basically your counter would be to change which stage they are at to suit the battle - pre or post corruption.