Our poultry is completely free ranging, in that they have total access to any of our land on this side of the road - they seem to know that crossing the road is not good, although we've only lost one very independent hen who decided to go over there anyway. They almost always stay within our fences too, even where our neighbour's land comes to within about 25 yds of the henhouses - no idea why. In fact they choose to range over only about 3 acres of the available ground. At night they take themselves off into their henhouses (converted garden sheds) and we lock the popholes until we are up and about the next morning, when they are let out again to do their thing. Dawn and dusk are still dangerous times, so we tend to lurk about then, with the dogs around. Actually the dogs are not much use as they are terriers, so tend to follow a smell back to the source and start digging, while the prey potters off in the other direction, laughing up its sleeve. They do bark a lot though which perhaps scares off some foxes.
We live in an open rural setting, with nearby farms where foxes are culled. Our entire holding is surrounded by double sheep mesh fencing, with a hedge between the two fences, apart from one short length - that will have to be fenced off as the fox soon finds it a useful way in. Even the double fencing plus hedge doesn't stop a thin and determined fox from getting through.
We suffer from city foxes released into 'the wild', which haven't a clue how to survive, so are a danger to our hens. In the main, the hens are safe as they are safely shut in Fort Knox for the night, but last year we were attacked in the middle of the day and most of our beautiful hens killed. My point is that true free ranging has it's dangers, and is never 100% safe. The only way to have any measure of safety is to fence in a large area with high fencing or electric mesh and the flock is not allowed beyond the fence. This ground soon gets poached though, so the suggestion is to have two scratching areas, with the house between the two, with a door at each end, so one area is resting while the other is in use. Depending on how large a flock you have, even this method will leave the ground covered with droppings and with no vegetation.
There's no easy answer and you just have to make your choice