It helps when keeping boy-only flocks if they can't see the females.
But every drake is an individual and it may work out just fine. If you're really against trying to find them a new home, it's certainly worth a shot.
You mentioned the fence is chain link? If the boys decide to fence fight...
I wouldn't write off the idea that no one will want them. Sometimes ducks can be hard to come by.
My mom had 6 drakes to rehome of varying breeds and was all upset because she assumed no one would want them. I encouraged her to put them online and she had three inquiries within 15 minutes. She...