Your probably over thinking your whole hunt. Not every duck or goose in the county is going to come to your decoys, even if everything is perfect. Just the way it is, ducks and geese have absolutely nothing else to do except try and survive everyday. That means they need safety, food, and water. If they find a good food source, they will probably keep using it until it's gone, or they don't feel safe. Most times it doesn't matter how many, or how realistic your spread is.
I explained this to a buddy one time while we were duck hunting a creek. Sitting by the creek, geese started to drop into the pasture. After about 20 minutes, there was about 250-300 geese in there. But all the while those birds were on the ground feeding, we watched flock after flock, fly right over them, and go somewhere else!! So I asked my buddy, what kind of decoys would we need to bring all the flocks that were flying over in? There is 250 live geese on the ground, and 1000 geese just flew over and wanted nothing to do with them. There is no decoys that could compete with live geese, it's just the other birds flying over had somewhere better, and pretty much nothing you could do would get them to come in.
It's just waterfowl hunting, if it was easy and the birds were predictable, it wouldn't be any fun!!