I assume you have read the following:
http://www.border.gov.au/forms/Documents/118.pdf
Based on your information, you have made some major mistakes:
1. No one really cares if you know any professionals. The key issue is the professional must know your fiancé for at least a year.
2. The list of professions is extensive and lenient (as it allows local non-citizen).
3. No one ever said the profession must be a local.
In this case, the easiest way is to ask your fiancé to get the identity declaration from Australia (it does not mean he has to return to Australia). Once it is done, the professional can send everything back to Hong Kong.