Confusions about S/4HANA Analytics Application BW Client

Hi experts,

According to S/4HANA Administration Guide for the Implementation of SAP S/4HANA On-Premise Edition (1511 FPS1) -> 2.3 Carrying out technical setup -> 3 Execute basic SAP Fiori configuration -> SAP S/4HANA Fiori Foundation Configuration -> S/4 HANA System: Generic Configuration for Analytics Application, I need to setup a BW client for S/4HANA analytics application.

However, I'm confused if an addtional client should be created or just use the ERP client?

If an addtional client is needed, which of the following senarios is used for?

Thanks and Regards,

Ning Tong