Then go Fort Knox on it using a heavier materials and aprons for your chicken tractors. It will still cost you something, no matter what you do. The eggs the chickens produce are not likely to pay for themselves anyway when you operate on such a small scale.
Your problem looks less complex than mine and might be fixable using an approach I used when free-ranging juveniles that went back to chicken tractors each night. The chicken tractors were in a row 10 to 20 feet apart. Either electrified poultry netting or three strands of hotwire formed a...