Duck drake ratio help!

[Duckfarts]

Hello! New to this board, and new to raising ducks as well. We currently have eight ducks, six weeks old that we've had since day two. Two Cayuga (1 drake, 1 duck), three Ancona (all three female), and three Swedish blue (still not sure on these guys, but pretty positive that all 3 are drakes - one is already getting his curly little tail feather). So my question is, will a 4:4 ratio work, or do I need to rehome some drakes? Or how do I go about adding more ducks, and what age do they need to be to make this work? They're free range during the day when we're home, and they have a 20x30ish pen outside with a house we lock them in at night. I'd hate to break this group up!
Thanks for any help

 

[Cluckcluck1215]

I feel one drake every 3-4 hens is good, but I would reccomend 5 if you can.

Good luck,

 

[TyKyra Lancaster]

Adding more ducks would be the best idea, try to get the females around the same age as the others.