Yes there are a few more things to consider. For a farm you want your fences to keep your animals in and keep other wildlife out. How can we do this? Think barbed wire without the wire. Yes, we use plants with thorns and spikes. Think blackberries, raspberries, currants.
Next we want a fence that is strong. Fence posts are often made from black locust which also have spikes. Trees like Black Locust, Honey Locust, Seaberry will do the trick and add strength to our living edible fence.
A good start for our fence will be a multi row setup all around the perimeter of your farm or property. Your first row can be a mix of Black Locust, Seaberry, and Honey Locust. Your second row planted just a few feet into the first row will be your berry canes. Given 1-2 years of protection from wildlife and this living fence will be a formidable barrier for just about any animal wild or domesticated.
Want to turn your edible living fence idea into a reality, see my article about finding inexpensive tree sources for more information on how to score all your plant material on a budget.