It seems your flock is fairly high risk for someone getting seriously hurt or killed - not that any individual duck is bad, but the combination and numbers have me concerned.
The things we can do are separate, bring in additional females, and rehome.
I do tend to intervene more - and yet, as Miss Lydia points out, some of the mating behaviors are not sweet. For now I think I would do what you are doing, Amykins, and let Bean know that you are her protector. I am Romy's protector. When I let all the ducks together, if our Bean (who is a...