From the very beginning, I have kept all 3 of my parrot cages in the same room. Their instinct is to be in a flock, and they seem to be comforted by being together. If I put only 2 in their cages, the other one seems lonely.
Keeping them in different parts of the house, you will hear them call for the others and trying to figure out who and what is in the house they can't see or get to. To me, that seems very frustrating. I also feel that the sooner they meet each other, if only from their cages, the better they will be about getting along, after all, they have had some time to safely get acquainted on safe terms.
Just my opinion. You will gets lots of them here. .