Yeah the NPC System would go in that direction, heck singular NPCs could be angry at their neighbor NPC for being too loud all the time and have a grudge against that one Asshole that keeps them awake at night. XD
Any sort of Hierarchy System for NPCs and Players will need a lot of work though, so that is definitely a later Feature to implement.
But at the very least Teams for the purpose of avoiding Friendly Fire and such will exist early, with some Members having a “Founder” Rank/Designation in that early version of the System, enabling them to decide who joins and who leaves the Team.
One of the Main purposes of my Game is to make pretty much everything possible, as long as it stays a Voxel. 