The AccountHierarchy class uses the
ManagedCustomerService. This service does not return any account statistics. If you wish to retrieve statistics, you could download reports using the provided report types supported in the API in this
link. You may read more on our
reporting basics on how to download your own report. Since it seems that you wish to download reports on an account level, I would suggest you to download the
Account Performance Report.
Let me know if you have further clarifications.