Witch King & Nazgul, ents vs Balrog

[genghissean]

1. Witch King can be recruited into any shadow army containg a Sauron unti. Now Nazgul are not units, but it seems to me that thematically the witch king should be able to be recruited in a region with a bunch of Nazguls. But a strict interp of the rules would say no. What is the official ruling?

2. If all units are eliminated by ents in fangorn, Sauraman is eliminated. Is the same true for the Balrog?

[Krieghund]

1. There must be a Sauron Army unit in the Army.

2. Yes, as well as any other Minion.