These are self inflicted wounds due to the conditions they’re kept in. I understand your options may be limited, but as others have said, this will just get worse if conditions are no changed. I would recommend reducing the number of birds in an effort to reduce the stress, which will reduce the injuries. Making no changes is very likely to result in illness and disease that could take out your flock.
It would be better to reduce the flock size if you can’t change their conditions rather than risk loosing the entire flock.
I understand that things are done differently in different countries, but other animals being kept in worse condition isn’t a safe standard to hold your own flock to.