Drakes can be a happy flock by themselves. Especially those raised together.
2:4 sounds like a bad idea. Like I said I had 1:5 and it didn't work out very well because he only mated with 3 of them. The more females the better, IMO.
If they want the drakes and are able to take care of them then I don't see any issues. Just because they have a big pond doesn't mean it's easier though. How will they get them off the pond at night? Do they want ducks anyway? I rehomed my drake and he is kept as a pet. I don't want to sound like you have to kill them if you don't want to just understand that we have to protect the females in our flocks because they can't do it themselves.
Well, I may have to bite the bullet and have one of them taken care of or re-homed quickly. I've noticed the WH drake balding on its back and wrote about it in another post with pictures. Went home for lunch to make sure they had enough water and check on them and the mallard culprit was just picking at them all. I'm convinced the balding on the WH's back is his doing. I'll have to separate him (I'm going to call it a guy because he's mean and I'd feel better about getting rid of a guy) and figure out what to do with him.
EDIT: After searching around, I'm going to separate him for a few days, then reintroduce him and see if the re-established order changes his tune.
Edited by wallawu - 5/26/16 at 12:08pm