With 3 proven pairs already, is there a reason you are wanting to set up additional pairs? Could you keep the unpaired ones in an aviary, all living as a flock, as wild birds do? You don't have to breed or pair them off, especially with all the unwanted birds in shelters and rescues that need good homes.
I have to agree with this statement, and here's why...(I bred for over 20 years, and I always followed a "community pairing" program). You can't make birds pair up, bond, or breed with each other, and every time someone tries (myself included) they just waste time. Birds are like people when it comes to their mates, their friends, and their enemies. If you pick and choose mates for each bird and just put them together, they will either hate each other and be aggressive, just ignore each other and be indifferent, like each other and bond but not bond as breeding mates, or they will bond and mate. Those are your 4 options and of you pick and choose you'll only end up frustrated. And by all means keep bonded, especially proven pairs together. You cannot just split up a proven breeding pair, put each bird with another bird you'd rather they mate with, and expect them to do it. Not only will they not mate with a new bird but most likely they will attack the new bird aggressively. So please keep any already bonded pairs together in their breeding cages, do not split them up because you will only be wasting time, causing frustration for yourself and for your birds, and you may end up with injured or dead birds in the process.
If you have males and females that are not bonded with any other bird, your best bet is to put them all together in a large flight cage or aviary and allow them to pair up themselves, it's the only way it will work to produce healthy, viable chicks. Once a male and a female are paired-off, always together, preening each other, feeding each other, etc., then you put them in a breeding cage by themselves. I call this "community pairing" myself, and it is the best way to develop bonded mating pairs. That being said, I don't ever suggest "community breeding", which means putting nest boxes in a large flight cage or aviary and not only allowing them to pair up but also breed and hatch/care for chicks in the community aviary. I know a lot of people do this and it's their choice obviously, but in my experience you will eventually only end up with dead chicks and dead parents from jealousy, aggressive hormonal behavior, etc. But that part is up to you. But by all means, if you want successfully bred, healthy chicks then do not separate already bonded or proven pairs and try to pair them with other birds, and do not just pick birds and put them together with a nest box in a breeding cage, you must allow them to choose their own mates to be successful.
"Dance like nobody's watching..."