I think if everybody takes a step back and look and some broader issues one service to provide all emergency services in this state wouldn't be that difficult.
There is a significant replication of services provided in all MFS, CFS and SES. Not only in primary response roles, but in operational and non operational roles. This includes Staff like VSO, Regional Officers and Training officers.
A one service for all doesn't mean that to be in the, lets say civil response (SES) that you'd have to be fire trained, vica versa, to be in the fire service you have to have training in Search and Rescue, USAR and Flood Mitigation. If you look closely, in a lot of areas throughout SA a lot of people already volunteer in colocated SES/CFS brigades/unit. Most members at Yankalilla already carry out both role, I believe this is also the case in Strathalbyn and many other areas.
It would be an easy transition and the money saved for no longer replicating staff role and equipment could be placed easily back to the volunteers, with improved equipment, training, support, etc.
I don't see whats so hard about it!