The situation has changed to this:
There are two birds up for adoption, one male, the other likely female.
If I adopted both and they attempted to breed, I would feel pressured to remove and boil the eggs -- which I can't do from an ethics perspective.
If I adopted only the male (to join my other two males), the female would be left potentially lonely and bored.
If I adopted the young(?) pair, they might make things uncomfortable for my docile, elderly English budgie.
I want to do what's best for each one of the birds, but I'm not sure that any of those scenarios can be considered falling into the "best" category. What's the the best scenario for the birds in this instance?