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Ok, so most of the necron units revolve around a lord leading battle formations into battle, but the lord is counted as a indepedant unit/character. Do we use any necron lord (overlord, destroyer lord, regular lord) or do you have to take a lord that is then given to the formation? Has GW talked about this/ FAQed it?
I don't know if GW has FAQed anything about APOC, but I would say it might be safe to assume and Overlord for anything that says lord. Otherwise we would be able to pull of cheaper formations and not really have a "true leader". Yeah, Lords are leaders in a sense, but not really as much for army commanding... And you shouldn't regularly get a lord without an overlord anyways, so it kinda makes sense, unless you DO have an overlord in the list. Thats my thoughts on it. But I couldn't say with any real certainty.
If you play a game, I would ask your opponent what they think, if I was to play against you I wouldn't really care too much if you used a lord for a formation if you had an overlord or character in the list, but some people are VERY much into RAW too an extreme. So I would simply ask until someone can give a 100% answer.