We recommend the Balanced flex package in most cases because in this configuration, the request/response traffic flows are segregated from the batch jobs and they have different threads and CPUs. This strategy helps in keeping large batch processes from starving the application’s request/response flows.
Whereas Granular requires more resources, complex DevOps practices and the most flexibility in terms of scaling. Moreover, you have the ability to deploy flex packages that suit your business needs in the best way and can group your services in a way that is different from the Balanced and Granular approaches for example, with respect to the frequency (or usage patterns). More information about deploying the flex packages can be found at Broadleaf Dev Central and Broadleaf Dev Central