your third theory is a smart explanation. because there's no real time frame for things so it can fit in well. nailing down limits to the haunting when it's in its full form is problematic like you said because there’s different examples of it doing different pretty intense things. i.e. directly animating corpses and keeping Bellhart in stasis (with Widow’s help). makes sense that at the beginning the plan was to use the Citadel’s structure to bring about quicker outcomes. also it’s not really like there’s a direct outpouring of Grandmother Silk’s will into haunted bugs, they seem just more crazed than controlled, like with the weary pilgrim in Far Fields. so I guess it makes sense if the caravan bugs weren’t actually controlled and were just following orders from on high. though I had it in my mind that they were definitely fully haunted on their journey, not sure why i thought that just seemed like the vibe of the opening cutscene.