I have 2 mallard hens, 1 small pekin hen, 1 runner/magpie cross hen, 3 scovie hens and 1 scovie drake and have no problems other than my small pekin hen needs time to herself away from the drake now and then. My pekin is my little special needs gal, she has a limp and is slower than the rest so she gets plenty of time to play outside of the pen by herself. I do let the drake top her now and then but stay with her and pick her up when he's done. The first time they were together he topped her so much she had cuts under her wings so the two of them no longer get time alone together. I hatched my pekin in the house and raised her inside for her first 3 months so she thinks she's human, she loves her duck siblings and has fun with them but doesn't get stressed when she's not with them. She's 3 yrs old now and she has been broody 4 times. One of my scovie hens (Bleenie) is a lap duck and has been since she hatched, she follows me around and will even stand outside my craft room window and sing to me...she just tickles me to bits. I love all of my ducks but I must say the best breed in my opinion is the Muscovy.
Michelle