Service Instances for SAP S/4HANA Example in the CSDM Model PowerPoint

[JoFletcher]

I am trying to understand why the SAP S/4HANA diagram Shows the Service Instance SAP Transportation Mgmt. Prod to depend on the Service Instance SAP S/4HANA Transport Mgmt. Prod? Wouldn't it depend on the Service Instance SAP S/HANA ERP Prod?