I think your right about feeding them becomes less aggressive, after feeding tonight i was watching him and most of the polys goes to his spot and he didnt care about them.
Keeping them well fed does help. Ive noticed most aggression form the endli happens pre feeding. Usually it will be the feeding day and the endli has an empty stomach so is a lot more active in the tank looking for food. I have seen the aggression actually stop when the food is in the tank because the fish is concentrating on eating and not bulling others.