there should be an option to disable random npcs being generated.
it's very annoying having to delete them just for more to appear in your save.
of course there's mccc, and if you don't want random generated townies at all, there's a mod called npcc by paulson. haven't played ts4 in a long time so dunno if it has had some changes, but it used to be a must have mod for my saves. yes, the game needs at least a few townies to fill the npc roles. i remember i used to completely depopulate my saves except for the played household, the bars were open but didn't have bartenders lol
you guys shouldn't forget that the random townies choices, their names, their clothes, their household, all is also part of the game AI, and we know how ts4 AI is. the amount of bugs don't help the cause either.