After about 8 or so slave girls, it began to feel tedious to max out sub/cor/rel but then I realize you don't need to max them out, there's no real benefit past like 50. Also the stats decay so scaling maintenance for all of them will be really tedious.Yeah I did all of those things and they all still died. It is just a waste of a hundred caps to give them a knife when there is a 10% chance they die every day and they make pennies. Also with that many slaves and characters without cheats it is completely unreasonable to manage their stats.
I agree that having them walk the streets is poor ROI even after Dom's protection and relevant gear but after getting Dom's protection the risk of their death decreases dramatically. I don't think I ever saw one die and I have 6 streetwalkers nightly so far.