Tactics against Necromancers.

Understood, thanks for the explanation.
One more thing – can you explain how Necropolis manages to gather 3-4k skeletons by the second month if they're forbidden from using almost everything? (if possible, in a simple way)

Even an average player can easily take any Fortress or Hive with 12 lords by day 8. They distribute Angels and Vivs to several other Necromancer heroes, and that's it.