your description doesn't even account for the possibilities with the interactions between NPCs, and between "unseen" players and NPCs, and further possibilities for interactions between "unseen" players, NPCs, and other NPCs who have to interact with the former 2 groups at the same time as consequences or even as part of their scheduled interactions.It would be...however. Remember this is a game where CR talked about fully physicalised NPC's, that would go to work, go home and sleep and return to work the next day even if there was no-one there to see them, these NPC's would be using processing power and server bandwidth even if no-one else was even on the same planet. So while yes you can use culling and tricks, I think that's something that hasn't so far been considered. I mean really in the above scenario you would just use some spare cycles to caclulate where the NPC should be at that time of the day and only render them when actual players get close enough to see them, but that's not what CR wants to do, he wants the cities to be living and breathing cities with physicalised NPC's undertaking day to day activities even when there is no one else there.
and on top of that, in this dream of a game, you are also have to take into account for the possibilities of interactions with non intelligent objects... like ships, cargo inside of them, all the ships systems in said ships, and even the fluid dynamics for a fluidic object in a bottle somewhere, all that claimed to be fully physicalized in real time.
time and again all that proves that even backers and defenders of this faith can't even fully comprehend what they're actually believing in.