Noone expects the Spanish Inquisition...

Class 1 = (Faction) Hideaway or Drone Cluster (easiest)
Class 2 = (Faction) Burrow or Drone Collection
Class 3 = (Faction) Refuge or Drone Gathering
Class 4 = (Faction) Den or Drone Assembly
Class 5 = (Faction) Yard or Drone Surveillance
Class 6 = (Faction) Rally Point or Drone Menagerie
Class 7 = (Faction) Port or Drone Herd
Class 8 = (Faction) Hub or Drone Squad
Class 9 = (Faction) Haven or Drone Patrol
Class 10 = (Faction) Sanctum or Drone Horde (hardest)