I don't want to alarm you any more than you already are and my experience is with Muscovy's only, but back when i first started with ducks and did not know beans about them, they just appeared in the river below our home, 3 drakes. found out later about dumping, I decided to adopt them oh they needed a home and someone to protect them, well I went and got 3 ducks to go with the 3 drakes, Big mistake, The girls chose one drake and that made the other 2 kind of 2nd and 3rd wheels, at this time they were still going back and forth to the river, I could not believe one day my husband and I were leaving to go some place and I looked down at the river and one of the drakes was beating the tar out of the other drake, since we had an appointment we couldn't stop but where they were we couldn't get to them anyway without walking down river, end of story, when we got home I did manage to climb through brambles and down steep cliffs to get the one drake back to my house, he died in the night and i know since I saw it with my own eyes this one drake killed him. Drakes will fight to the death, I don't know if all breeds are like this but Scovies are. I wouldn't take any chances in that the drakes may injure one another severely and or they will kill or injure one of your females. it isn't worth it. Sorry for the long story but I have 3 drakes now and 10 females and I have to separate my boys quite often during breeding season. And I will not let them abuse any of the girls, if they get too rough where someone is hurt they are separated.