@1LoveS1ms Very interesting idea! I love it! 🙌
As a work-around/alternative I have made and played a duplex (and you could make an 'apartment' the same way) where I merged two (or more) households into one (you could even do this with roommates to increase the capacity to 10 Sims, and even add a butler on the lot to take care of all of them - which brings it to 11 Sims on the lot - with no cheats).
Use the door locks to create private apartment areas, and even common areas (maybe a laundry room, rec room, storage room, etc.). This way you can control all of the Sims on the lot except the 'roommates', and wherever the 'roommates' bedrooms are assigned could be a different apartment(s), if you like.
You could get very creative and keep very challenged on that lot! Any maid, gardener, handyman, etc. could work the whole lot!