Likely cockerels. Yes, they do grab a hold of the neck feathers, sometimes the comb. But where do they place their feet

Backs and/or on the wings. Mount/dismount can be rough, even if the pullet/hen squats and is submissive - he still has to climb on - there's big feet, nails (claws) and if old enough, spurs that drag across the back and top of wings.
If the pullet/hen is not submissive - then he grabs whatever he can to catch her - often times the the feathers on her back. One rooster can cause some damage - 2? That doubles the chances of damage.
Look at he photo below - this is really a good one - shows the positioning of feet and how they grab the head/neck.
REF