I have dogs as you see below. I have a 90 x140ft backyard with a 5' chainlink fence. I want to know if I can set a 30 x 90ft Barrier fence to free range, So it keeps the dogs out and the chickens in. I have a enclosed run attached to the Coop now.(About 128sqft) How tall does the fence have to be to set the point? Mind you I have a pain in the behind Bully.So Post holes are well need in this project. She Already took out a stud on the coop from bull rushing it. But she is too dumb to figure it is a weak point. (good for me till I notice to fix it)