Ammunition Factory appears twice in the technology tree.
More generally, these should probably be replaced with generic "T2 Unlocks". When a Wellness or Exploration event asks me to pick a Tier 2 building to unlock, I'm unable to open the tech tree to see if that building type is somewhere ahead of me in the tech tree.
Yeah, the Modular Farm building got replaced with a second copy of the Ammunition Factory. It is fixed for the next update.
Buildings offered in the other systems are only ones not already in the tech tree. There should never be any overlaps where you can get a building from Wellness, Defense, or Exploration that you would later get in the tech tree.
