I free feed in a round feeder that you fill in the middle. I also scatter all over the coop so they can scratch and I feed them kale, and other garden veggies I also scatter treats like flax seed and other seeds they get all of these things daily. There is no shortage on food. I am more worried I am over feeding!Do you ration food or free feed?
I don't have experience with bully chickens preventing others from eating, but it stands to reason that a chicken can't guard the feeder every possible moment if it's always full and, even moreso, if there are other things to do in the run than stand next to the feeder.
Also, what kind of feeder are you using?
Is there room for all the chickens to eat at the same time?
It stands to reason that scarce resources -- rationed food or limited space to access food -- would tend to trigger food guarding while abundant food/access to food would not be protected so jealously.