If you let them run free, be prepared for regular loss from hawks. The only way to keep them from picking off your birds is to keep them secure under netted and wired runs at all times. A good rooster can alert, somewhat, but he likely won't deter.
Just because you are on the property won't stop them. My husband has stood and watched a hawk dive bomb and hit a hen within feet of him. They can become very brazen and are fast. You can't stand watch 24/7.
We lost regularly until we put up bird netting between trees and confined them better.
The other option is to find a good large guardian dog and let him stand watch.
BTW...the hens won't mind staying in a nice roomy run. They actually prefer safe familiar range to being picked off in unfamiliar territory. You might consider a chicken tractor pulled to various locations.
LofMc