As I said, if what you say is true, then perhaps WA Vets have chosen not to follow the advice from their representative body. Although to be fair, the advice is up to 3 vaccinations. West Australians do tend to be a little remote from their east coast counterparts and so it does not surprise me that some do things differently.
Either way, the Vet that has advised 3 vaccinations in this instance is not wrong. He is simply following the advice of the Australian Veterinary Association. Whether or not the OP chooses to act on the advice of their Vet is their deal.
I don't vaccinate beyond puppyhood.