Island ATMs Serviced by Armored Car

We are currently replacing our ATMs and due to security reasons, the ones that are on islands (not attached to the branch) have to be serviced by Brinks. I was told by Branch Admin that when they are replenished, Brinks will remove the residual cash, bring the cash back to their facility where they will count it, then it will be shipped back to the branch with the next regular cash order. I questioned them about the process of proving that residual cash to the balance in the ATM when the cash was removed and they weren't sure how they were going to do this. They were just going to count the cash Brinks returned and assume it was what the ATM balance said it had on that day. Is there anyone that has this similar situation where their remote ATMs are serviced by armored car, however they receive the residual cash from the service? How are you reconciling the cash received to the actual balance? Any detailed information on processes in place would be greatly appreciated. I know that we will never be able to audit these machines, therefore I'm trying to ensure there are proper controls in place that would give us assurance that the cash received is accurate.