Your plan should be fine, but I will tell you from experience that any determined critter will do whatever to get a free chicken dinner regardless of your security measures. Ive had them to chew through wire, tunnel under wire, and even pulled tin of the sides of cages. Your best bet is to keep the pen close to where you can keep an eye on things and if you were to hear something going a muck, go check on it.
Coyotes and Raccoons particularly. Foxes and Coyotes will also dig under the netting. If you're well away from your neighbors a 22 rifle is a good critter deterant.