Assisted living, if it is a reputable place, is usually for adults who can live on their own with some assistance. We have a very nice one here that some locals have checked themselves into, when they can't take care of a home and property, any longer. My fil is in the the care center part but the assisted living part, has activities, outings, etc...
It might help them to be in one, to assist them in learning to live alone, get their physical therapy, and ensure that their diet is properly seen to also. If all of the adults go to the same place, they will have each other, and can mingle with others there. I'm sure that those over the case will ensure that the facility will be top notch, and, when ready, they can check themselves out, as they are adults. They need to focus on themselves for awhile, but an apartment on their own, or being told what to do in another home setting, may not be best for them. I'd also think that they had some say so in the decision.