4-5 Extra pilots based in Broome for an extra aircraft? - forget medical staff, you fail to win the pilot/jet case yet.
So on your numbers if Broome has 2 x PC12 and 1 x PC24 in Broome then the RFDS need 12- 15 pilots based in Broome.
So we have at any one time 9 - 12 pilots sitting around doing nothing!
The reality is there may be 4 off duty pilots while 3 are flying - that's 7 pilots based in Broome in total.
There is no need to have a pilot based in Broome to cover a pilot on holiday or if a pilot get sick for a number of days - in this case a pilot from Perth is sent to cover for the short term absence. If it is for the case of planned leave then a training pilot can be sent to be well utilised while in Broome.
The roster is set so certain pilots (possible 1 or 2) are on say a 12 hour emergency on call and I see this can even be extended to 24 hrs - there is an extremely low chance of actually being called in but it can cover for occasions that are rare like 2 pilots calling in sick at the same time. The remaining 5 or 6 pilots cover days off and duty.
I doubt there is "fat" in the number of nurses, they work dam hard and certainly do not have HARD duty limits like pilots have enforced by CASA - a nurse can work much more than 2,000 hrs a year.