Mixed flock - probably a dumb question

[Silvester]

I currently have a Rouen (male) and three Pekins (two males) and they don't seem to get on well at all. I think I can mostly write that off as "too many males".

How well do different breeds of ducks get along?
I'd like to get more females of different breeds, but I want to know they will at least be mostly civil.

Any advice?

 

[DUCKOBSESSED]

I have all my different breeds living together. It is most likely 3 males fighting over 1 female. They could harm her or kill her.