I have no experience with guineas and my birds don't free range but I did have a thought-if eggs aren't important to you, why not keep a flock of just roosters? You could find an endless supply of them for free that you don't have to raise up from chicks and my understanding is that roosters can be housed with each other pretty easily provided there are no hens to fight over? If one gets picked off by a predator, you can easily replace it. Just a thought. I've never kept a bachelor flock before but I know a guy up the street from me does it for this exact reason. He is who gets all of my excess roosters