statistically, there is currently one CASA staff member for every VH registered aircraft in Australia (that’s my maths, so willing to be corrected if wrong).
You are wrong. The number of VH-registered aircraft and the number of CASA staff members are easily ascertainable on the electric interweb.
I think what you’re referring to is the old DCA which included the functions of what are now CASA, Airservices and the aviation ‘bit’ of the current Department of whatever-it’s-called-this-week, and which ‘ran’ all the airports that are now assets for the generation of private profits and ‘ran’ all those aerodromes that are now a pain in the backside for so many local Councils and the target of property developers.
There are many things for which CASA may legitimately be criticised, but the number of staff equalling the number of VH-registered aircraft isn’t one of them.