if you are planning on completely free ranging you will want a rooster with the flock, have you checked what predators you have in the area?
We had 2 roosters and a big breed drake with our free ranging flock, the main, aka mean rooster, and the drake would defend even against hawks and the pair made even the eagles think twice while the other rooster would get the hens to safety and keep them calm.
one thing to think about whether free ranging in a large enclose area or true free ranging is there enough cover in different areas for them to take cover from especially aerial predators, a ground predator depending on whats in your area, they will either be flying up to get away from or running back to wards coop.
I would also read up on the Predator Thread if you plan on free ranging but with good planning you will keep your losses to a minimum. one predator most don't think about is feral cats, if they are hunting in a pack they will take down a full grown hen.