Should I net electric the whole desired area, or half of it?

I'm trying to establish a food forest (saplings [currently] with a rhubarb understory), and am having a massive invasion of Canadian thistle, and grass, so I'm contemplating purchasing 25 jersey giants next year, but it will take 2 rolls of electric mesh (300'). Should I just rotate the chickens every week (with a home made coop on skids), or so, or net in the whole area including the trees coons may jump out of to get to a tasty meal?

As far as protein in the area goes it's a wine cap bed with lots of insects to hunt.

Those dots are a bird house (house wren/blue bird) perimeter that I put in last year

My suggestion is to have the chickens on rotation. Chickens that remain in an area for an extended period of time can denude a soil. Another challenge that can happen is a buildup of chicken manure where they like to hang out seeking shelter from rain and also shade from the hot sun. This manure can, if there is enough, result in a nitrogen burn and can take about a year to resolve itself. As far as raccoons go, I believe it is possible that if the trees are dense enough, they can climb one on the outside of the fence, traverse branches to another, and climb down another tree trunk inside the fence. Another predator that I suggest taking into consideration are owls. I've lost a couple birds to a great horned owl when the chickens went out too early in the morning. I have an automatic coop door opener to prevent this, but I have to stay on top of keeping the timer adjusted as days lengthen or shorten. I have it set so the door doesn't open until the sun is really appearing above the horizon. In my experience, owl activity seems to have stopped when the sun is peeking above the treeline. Having said all this, I myself use electric net style fence for my chickens, and since I've been using it, I've never lost a chicken to a four-legged land predator. Hope this helps.

I'd agree with James. You'll be wise to keep them moving. I'm not even sure I'd only move them once a week - it might depend on how many, in the total area of the tractor you're using. But, I would keep them covered, from above. Mine are free range, during the day, then locked in, at night. We've had raccoons, foxes, snakes, coyotes, wildcats, and even bears in our area, as well as hawks, eagles, and owls.

I have 9 chickens on an area double that size. It was hard to guess how much area that X-number of chickens could graze without over-grazing. It came out  alright when it was mostly clover growing from April to July, but after that the various weeds like white-avens, smartweed, and thistles started growing and the chickens would NOT touch any of them so I finally had to mow it all. My point being, don't expect chickens to clear the land for you (if that's your goal) especially if there are things they don't like to eat. In your area, you might end up with over grazed dust between the thistles.

The fencing strategy I used was T-posts with 6 foot poly deer fence, to which I added 3 electric strands at the bottom. The fence wires (polyrope actually) stand out from the outside of the fence on 5" insulators. This is all connected to their fort-knox coop with auto door so they're safe at night.