In order to get chicks, one must have a roo + hen + heat. A fertilized egg is in suspension, and will not form a chick until about 24 hours of continuous warm heat has been applied. This allows a hen to lay an egg a day in a nest, and when the nest gets full enough to suit her, she will begin to set. All of the eggs will hatch at the same time, as they all began to grow at the same time, they wait for the heat. She is not in danger of eating a partially formed chick. Chickens themselves are not interested in the eggs, fertilized or not until they have enough daylight hours, and the stars line up so that they are broody. I spend the spring praying for a broody hen!
That being said, I don't know that I will change anyone's mind.
However, if you want to hatch chicks with a broody hen, you will need a roo with the hens most of the time, as no one knows when a broody hen WILL go broody, and one must have the eggs ready when she does.
If you want to hatch chicks all year long, in an incubator, well, you could do the set up, you suggested, but I am going to tell you it is not natural to the chickens or the flock, and they will try an thwart this plan every chance they get. They will not like being separated, and roo will really not like it.
If you want to hatch just at specific times of the year, you could probably borrow a roo, and have your wife eat store bought eggs while you are waiting.
But really it is a lot of messing around for no real reason.
MrsK