Our recommended best practice is to adopt a structure where each campaign consists of a single ad group, targeting one specific ASIN (SKU). While setting up this structure may require a bit more time initially, it facilitates meticulous campaign management, providing ease and efficiency in the long run. This approach allows you to maintain a comprehensive overview of each campaign, making adjustments and optimizations more straightforward. Though the setup phase may seem time-intensive, the benefits in terms of streamlined campaign management and improved results make it a worthwhile investment. 

If you have any further questions or require assistance, feel free to reach out. We're here to help you optimize your advertising strategy.