I free-range quite a bit and rely upon roosters to reduce loss of juvenile chickens to hawks. My chickens are full-sized with many being game chickens.
Silkies are a different story. They should be confined with every protection measure possible. They have limited ability to see and have a large number of mutations making them extremely vulnerable to predators of all colors.
Particulars of male silkies I am not familiar with although they might be adaptable to bachelor pen keeping. If not, then pen excess males singly. Otherwise re-home or eat them.