I agree that Wraithguard and Wraithlords are easier to control than Robots. Robots are very restricted in what they can do, and it isn't that easy to snipe Warlocks and/or Farseers, providing you are reasonably careful.
As for the costs, if you're unhappy with those, Magnus has pointed you in the right direction regarding an alternative points system, which you could use, since the costs for default NetEpic Gold are not going to be changed.
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