That's correct, my Discus are of different sizes. The larger one does try to chase off the smaller ones, but they put up a good fight for their favorite food. I feed them enough so that when the larger Discus are full, they leave the others alone, so everyone gets their share.
I find that I have to feed in just the right amounts everytime, to make sure when the smaller ones eat, they finish everything. That's where the second cone may come in handy, to spread out the aggression during feeding. There's only one real bully in the bunch, and he can't watch both cones if they are spread apart.
