family members are NPCs? my brother is lets say an NPC miner so i set him to work in one cave and dig ore for me? he will be there in real time? digging in the day, sleeping in the night in my house?
the best game i've ever played was ultima online on a small rp shard with unique rules and you could "buy npc people" to do stuff for you (at that time only to sell in a shop). But I can imagine they could do many more things (sell, mine, do blacksmithing, alchemy, collect plants, beg, steal, farm, breed horses...) It would be cool and feel alive, those all npcs would be "real" people, they'd belong to somebody and would be making things that are making sense.
and rich people could have more npc, while stupid fighters/soldiers would be alone and horseless.