Welcome to BYC!!
While it may work out okay, there is more potential for it to not than for it to be successful and peaceful.
That said ----- we did have a 2:1 group of ducks that lived very well together the entire time we had them. In our case, I think part of the success was that Clyde, the older/larger male (a black swedish), simply had little to no interest in amorous activities. He was content being the patriarch of the group, providing security, overwatch and leadership - but leaving the more active male stuff to our "surprise" male Rouen (Bonnie-Bob). Even Bonnie-bob was not *that* hormonally driven, he'd take a turn at Judy duck now and again, but it was not high on his list of daily activities. I think the overall lack of hormonal drive is what worked to keep our three from becoming a problem.....they all lived together more as room-mates than as mates.....which worked out well for us. We had them all together for a little over two years -then in the course of about 9 months lost Judy to a fox, Clyde to old age and then re-homed poor, lonely Bonnie-bob to a large flock at the farm of a friend of mine. We wound up with Judy as a favor to someone we knew- and then got Bonnie-bob and Clyde because a) she needed companionship and b) she needed someone to teach her how to be a duck.