Society Finches are the sweetest of all finches. They will sit each others eggs and many breeders that raise Cordon Blues will also have Society Finches because the Cordon's are not good at sitting tight on a clutch but you can put their eggs into a society nest and they will hatch them. You can even have 2 males with one female and once the female decides which will be her partner both males will help set the eggs and feed the babies. I have had so many societies in one nest, even with more than enough nests for everyone, that there was barley enough room for the eggs to hatch, and everyone fed the babies. I have also had finches take over a zebra finches nest because the parents weren't sitting the eggs. The societies hatched and raised the zebra babies. So even though you add one or two more nests, so they will have a choice, they may still move in with the original pair. You can put them together whenever you want to as long as you know their healthy. As far as Societies go "the more the merrier".

It's always best to quarantine New birds to make sure they are completely healthy. But as far as mixing societies with nesting birds you should be fine as ling as there are other available nesting areas they tend to be easy going while sitting. Mine never seem to get bothered.

It helped to get an answer from someone who owns the breed. great info thanks