As far as putting them together, the short answer is don’t. Not all birds will get along, even when you get a male and female of the same species. This is one of many reasons why is it so hard to breed birds. You can’t force a pair to get along and usually when they fight every time, they simply are not compatible. There can be known reasons. The most common being that one or both birds are pets and enjoy humans as companions. While this can change the longer birds are together, some birds are so bonded with their human that they will not accept a mate as long as their preferred human is around. Age can also be a problem. If these birds are only 5 years old, they are just now getting old enough to think about breeding. If one is much older than the other, the younger bird may not be mature yet and the older bird will get frustrated and aggressive in this case. But if these birds are at least 8-10 years old and both about the same age, then for whatever reason, they are not compatible.
As to the plucking, you need to take the male to an Avian Vet to be checked out. There has been some correlation between avian bornavirus and feather destructive behavior, so a test for this is a good starting point. The Vet will recommend several test to rule out a medical cause. Most plucking does start due to a medical or hormonal issue, but then the plucking can become a habit. So he needs to be treated medically as well as address his behavior.
Thank you for asking Lafeber,