I really only pointed it out since the SHornets just recently celebrated a decade of service in the RAAF.
Personally, I suspect the SHornet selection without competition had more to do with there having been a gov't eval done once it was determined that the F-111 had to go by 2010 with the goal of determining what could provide the RAAF with a replacement strike capability as quickly as possible. I do not know for certain that such an eval was done, but it would be logical to assume that someone in gov't checked to see what aircraft were available for ordering.
The RAAF was able to start getting the SHornet in service, in Australia, about three years after signing the purchase contract. Part of this was the willingness of the USN to let the RAAF 'cut' the production order queue. Another part was due to the similarities between the Classic Hornet and the SHornet, which made it easier for personnel to be transition-trained to the SHornet. I do not know of another fighter aircraft of comparable capability to the SHornet, or appropriate for a strike/swing role, which could have been gotten into RAAF service in Australia within three years from the signing of the contract.