All of them are trouble, and should be handled by people who don't have other kids. Yes.
Bringing in a troubled-youth into your home, with your own school-aged children, is a disaster waiting to happen. There will be abuse, stalking, molestation, experimentation, and all kinds of other things. That's what happens when troubled youth get put into regular homes. I've seen it plenty of times.
We are talking about babies. There is an infinite number of couples available who will take one. They will ALL get families.