I'd rather keep the dorms as they are as much as possible (so I don't have to change plans / go all the way back to page 1 and edit the CS :D) so perhaps add the others as NPCs or have some dorms with 4 and some with 3? I think that would better than having all with 3 since that cut down interactions a lot more than having some 4s and some 3s.
Also,
@Lady With Class if he "gets inside your head" I'm guessing that would manifest as an urge to do something? If so, I imagine anyone with good self-reasoning skills would probably be able to realise they didn't actually want to do it. Or maybe, if it carried some negative for them then they'd stop and think about it first. I mean, if you just follow your urges without reasoning you're a sociopath :D