I was thinking of getting a pair of Call ducks, but BEFORE I do, I wanted opinions on if people think it'll work. I have one Khaki drake & 3 ducks: khaki, rouen & pekin, who are very gentle. The drake is definitely in charge of his ducks. I'd love to also get a pair of call ducks, but don't know if introducing some smaller ducks will just be a major problem. Any thoughts?