In reading this forum, this dynamic sounded fairly normal. They are a brutal bird! I guess next spring will be really hard to watch during breeding season.
Good memory! Yes, my stinkers are 3mo. I ordered 50, received 57 or 58, lost one the first morning. Sold half and kept 26.
The outcast is a light bird but I have several. I wish I could have made the outcast the buddy bird for the injured one but I can’t identify her on the roost. She is permitted to roost but usually gets jostled around a bunch until she lands near more tolerant neighbors.
The injured sky blue and her buddy have been released and are glued at the hip. That would have been an improvement for outcast.
Sky blue’s two splashy pied (or pinto?) friends have changed their behavior toward her after her week of confinement. Guinea social dynamics are intense.
You mentioned an outcast may be smaller. The range of sizes surprise me since I know the birds are exactly the same age. One pied/pinto is noticeably bigger than everyone else and knows it. Some are little. Quite a range given they are the same age, from the same breeder, and managed the same since day one.