I've got some aggression issues as well. Female on female, female on male, male on male, male on female.
My observation is that it's all about housing/density. Most pens have ample space normally. But when there's a fight, the one that's being picked on just can't get away and the aggressor...
Be aware that the purina game/turkey starter comes in the same bag as the chow growth/plumage, but the actual contents will be on the small white label. Look for protein ~30% or something on that label.