My experience with these mining contracts and their requirements for two crew is, They require two endorsed pilots onboard, this barely resmbles two crew.
A few years when I was involved in this type of operation I recall watching companies who were tasked with these operations using bare CPL with no type endorsement simlpy to cover the requirement.
I believe the RFDS and other simliar operators such as Pearl,[Noerthern Territory Aero Medical Services] who do exactly the same job, can all stand on their record.