Well I’m kind of a newbie but I have chickens and ducks together in the run and the coop
Ducks are messier and need way more food and tons of water , it makes it double the work. Ducks need niacin and green vegetables and a pool or something they can get in to bathe daily . When I put new chicks out My ducks will slightly bulky them for a day or two but then they are fine . I haven’t had to much of a problem. The ducks don’t perch and need a bed or box on the ground . That’s about the extent of it . They are doing fine together