The short version is that if all you want to do is force more than 8 sims to live in one household, you can do that with a one-time MasterController command.
( Edit: I see that Sarah_Sims got here and posted an equivalent link as I was more slowly typing this out.)
This FAQ entry should be a good place to start reading. Many of us of course use all of these mods for all kinds of different reasons already anyway. Which ones you need to use and when depend on what exactly you are trying to do. There are several NRaas mods that concern themselves with how to create and manage households with Greater Than 8 sims. You should be able to start your own threads, if you could please, for new questions that are not related to existing discussions. Retuner is one of our mods, the discussion there was specifically about that one. I have moved your post to its own thread as it was not on-topic for the Retuner discussion.
