Overcrowding on AREA isn't always the problem. If you only have one feeder or several feeders too close together, they can be 'overcrowded' because the more dominant birds will push away the less dominant. Also, housing space, roosting space and watering space can be issues all in the same...
Sounds like overcrowding to me. I've never had a single issue between turkeys, guineas, chickens, muscovies, welsh Harlequins, and geese - because mine free range 24/7. If free ranging isn't possible for some reason (I can free range because I haven't lost a bird here in like 8 years to...