Maybe you should read up on some things. [Here he starts counting them off his fingers.] One, droids aren't the only ones who come into the barrier. There's scientists who have snuck in before with the intent to kill us, baskers for hunting fugitives down, and in the past altered the weather to flood us out.

Two, the Third Party have breached barriers in other enclosures with the intent of wiping out villages. This site was the focus of their attack years ago, and could be again.

With a good enough surveillance system, we could see these threats coming. Hours or minutes - any extra warning is extra time to prepare.