The granularity attribute of the intermediate dimensions that are used to resolve many-to-many relationships should be included in all aggregation designs

Best Practices Recommendations

For best performance, the granularity attribute of intermediate dimensions that are used to resolve many-to-many relationships should be included in all aggregation designs.

Aggregations on other attributes of the intermediate dimension might still be useful when the intermediate dimension is used directly and the many-to-many dimension is not used in a query.