Something odd happened during a battle at Revere Satellite Array yesterday.
I had just returned from Far Harbor, and I was on the beach a little ways south of the Nakano homestead. On a whim, I called in a Vertibird and directed the pilot to fly me to Revere so that Danse and I could slaughter some supermuties. As the bird landed, synths at the fishpacking plant took a few pot shots at it, so I strafed the building with the minigun as the bird took off. I distinctly remember seeing my Coastal Cottage settlement pass by down below as I continued to fire at the fishpacking plant, even though I suspected the plant was out of range by then.
As the Vertibird continued south, I fired on additional targets of opportunity along the way (Dunwich Borers, Hub City Wreckers, etc.). I don't think I actually caused much damage to anything. The weather was a bit foggy, so I couldn't pick out distinct targets. Finally, the bird dropped off Danse and me at Revere, and we proceeded to unleash upon the unsuspecting mutants. A couple of minutes into the ensuing battle, I noticed that there were settlers engaging the mutants as well. I didn't see anything odd about that at first, as residents of nearby Finch Farm frequently end up drawn into battles at Revere and Saugus.
Then I noticed that my FPS had dropped dramatically. As I looked around, I realized that there were dozens of settlers participating in the battle. I lost count at thirty, and there were far more than that. Finch Farm only has 23 settlers, so they didn't come from there. Had the settlers at the Slog somehow aggro'd as well? Ir was rather far afield for them. In the middle of the fight, I saw through my rifle scope a distinctive Mr. Handy robot engaged with a Supermutant Overlord; I recognized it as a robot I had assigned to farming duty at Coastal Cottage. What the hell was it doing so far south?
Once the mutants were dead, the settlers all started to drift away in small groups, returning to wherever they were supposed to be. It was late at night by this point, so presumably that would be in their beds. I followed them. Some of the settlers had indeed come from Finch and the Slog, but the others kept walking right past those settlements. The group I was with dwindled as settlers peeled off to head for the nearby settlements. I followed the last stragglers all the way to Coastal Cottage, where they rejoined the settlers who were already there, and who had presumably never left.
In the aftermath of this curious incident, I found myself pondering how all those settlers came to be where they were. Had they all coincidentally wandered away from their respective settlements, and just as coincidentally happened to be close enough to Revere array to be aggro'd by the battle nearby? I have observed settlers wandering around in small groups at night up in Far Harbor, and they will aggro if I engage nearby enemies. So it is within the realm of possibility. However, it seems unlikely that so many roaming settlers would happen to be right there near Revere at the same time.
Then I remembered my Vertibird flight. The path of that flight passed over Coastal Cottage, the Slog, and Finch Farm - possibly also County Crossing as the bird circled around to approach Revere from the southwest for landing. Was it possible that as I flew over those settlements, randomly firing the minigun at targets below, it caused some of the settlers in those areas to enter some sort of aggro state as allies? Was it further possible that the game then teleported the settlers to my vicinity in response to some pathfinding code priority, since the settlers were lagging far behind me?
It would be intriguing to hear from someone who is more familiar with the game's settler AI. Has anyone else experienced the inexplicable arrival of an army of settlers in the midst of a battle, seemingly out of nowhere?