Also - if this hybrid architecture is available - does it pick up network model, basetiles all from ArcGIS server?
ArcFM Mobile clients can communicate to our cloud service, esri's cloud services, or your own internal ArcGIS Server/ArcFM Server instances.
The client would not connect directly to a database or sde but ArcGIS Server instead. So for example, one of the layers the ArcFM Mobile client could be configured to communicate with could be a Dynamic Tile Layer of your FM network hosted on your own internal servers behind a VPN. This would require you deploy a ArcGIS/ArcFM Server instance.
Hopefully this helps clarify your questions.