Post pics... cockerels should be easy to pick out at 3 months old...
That whole handling thing is crud... it will teach them that you handle them whether they like it or not. And that you aren't hurting them. But tameness and desire for human interaction is very individual... Maybe it will work better for certain species.
I might use a bottle of nail polish (or even house paint , whatever I can get my hands on

) and get a nice mark on the head or shoulder of my attacker so I COULD identify them! And soon thereafter invite to dinner.
Or different color polish placed on each after roost so they can easily be distinguished... ankle ties can be hard to discern color when it's dark or things are happening fast. Spit balling ideas... I know how hard it can be to tell some apart...