Air Nelson took over from the F27 operation. It was to effectively stop the pilots swapping from fleet to fleet. Now you start on the Saab and if you want to go up the ladder you apply to the next operator, Mount Cook or Air NZ.
Under the old system every Saab pilot would get a go on the B737, B767, B747 etc. Some of those early Air NZ pilots are rated on everything at some considerable cost.
This is an example of pigs at the trough with no thought on how the trough is replenished.