Even 3 NPCs with Class 3 Guns, hitting your hull 8 times a second makes it impossible to aim, cause the whole screen whould shake like crazy. It's not just about "zomg npcs killed me! Q_Q" Its about "Why should NPCs be there when they do No Good, and just ruin everything for everyone? Or at the very least, just annoy everyone?"
Even if we remove all Guns from NPC Ship, still 9 NPCs is one hell of a Ram-fest, which makes fighting impossible. So, the point is not their Number or Firepower, the point is either getting rid of them completely, or finding a way to control them.