Your chemical company has a procedure in place that requires sales agents to manually check documentation for customer orders. You currently utilize a pull subscription in Google Cloud Pub/Sub, which allows these sales agents to retrieve the order details necessary for processing. It is crucial to ensure that each customer order is processed by only one sales agent to avoid duplication of work and potential errors. Additionally, it is important to maintain the simplicity of the current workflow without introducing additional complexity. How should you proceed to achieve these objectives?