Hi Barry,
Please look at the communication channel diagram.
Setup of SAP Fiori System Landscape - SAP Library
The WebDispatcher redirects
1. All UI http requests to the frontend server
2. OData requests for transactional apps to the frontend server -> backend server
3. Factsheets search requests to the backend server
4. OData requests for Analytical apps to XS engine
The item 3. means Factsheet search needs Suite on HANA.
The item 4. means Analytical Apps work with HANA side car deployment.
Regards, Masa
SAP Customer Experience Group - CEG