In sims 4 they'd sadly still act the same, I put an evil mean guy in a house and he became friends with everyone. Because sims never seem to do interesting interactions on their own.
Even if you clearly put in that they dislike something, they will do it anyway. Vegetarians eat meat too if another sim serves it, and then gets sick and mad about having eaten it. It's why I don't have vegetarian sims any more in Sims 4.
In sims 3 I had some interesting situations because of traits. I had a good and evil woman in the same house, when moving in they talked quite nicely to each other, seemed to get along until they discovered those traits of each other. They disliked each other ever since.
I also had this loner rockstar guy in the house, I am not sure of his traits anymore but he is the only masochist sim I ever had. He kept flirting with the evil woman, and she would slap him or beat him up after every attempt, sometimes she'd beat him first, and he'd come on to her after that.
And he never made a pass at the good woman who also lived there. Or the lazy slob guy or the geek guy who also lived there. Did it all on his own.
I really hate how they do nothing interesting in sims 4 unless you tell them to do it. I always like to see my sims do their own thing, make their own friends and pick their own love interest(s). Make their own enemies too.