Hum, now that's something I never though of either. A dog biscuit once a day between them maybe??? Healthy, good for teeth??? That's true about the difference in who eats how much. Cupcake is approaching big kitten size and Blueberry is large gerbil sized. Different breeds and different litters so way different sizes.
Cupcake is the first in the food dish and everyone else grabs and runs around her, they don't fight at all. There's just an understanding that Cupcake gets first pick of the goodies.