Hi,
These chicks should have very little stimulation other than being fed at this age. You can interact for a few minutes before each feeding. But mostly they should be kept in very low light to dark, just as if they were in a nest box. They are growing and developing and are not ready to be exploring yet. If they were with the parents, they would be in the nest box all the time, with one or sometimes both parents. The only time they are awake means they should eat. Your chicks are not bullying each other – they are trying to eat because they are overstimulated. And they would be cuddled together for support and warmth. In a full clutch, the oldest can be a week older than the youngest. But since they mainly sleep, and they would have a parent sitting on or with them, the size difference isn’t a problem. Their instinct right now is when awake, they should be eating. Otherwise they should sleep. Once they have most of their feathers except for tail feathers, they emerge from the nest box. So until you feel these chicks would be able to climb out of a nest box on their own, and fly to the cage floor, they are not ready for anything other than a small amount of interaction, being fed and then sleeping.
Thank you for asking Lafeber,
Brenda