One significant quote was found by Bushranger on this this forum. Read all of his posts on that link.
That feat was accomplished in the late 1960s, yet complied with the Operational Flexibility intent of DWP2009, Chapter 8.61 - Australia cannot afford to maintain a large number of narrowly applicable capabilities. The future development of the ADF is to emphasise, wherever possible, operational flexibility and multi-role employment in the ADF's systems, platforms and organisations. This might involve, for example, achieving greater platform flexibility by way of inter-changeable modular design and construction techniques.
He also has the best short summary of why the Sea Sprite for Australia died.
Also what is surprising is the stripped-not-equipped approach to Australia's purchase of the Romeo. I am surprised at the idea of not keeping full ASW ability on this airframe. The problem is when you need ASW ability on the airframe, you also need a well trained community of ASW operators that have been created by lots of peacetime training.
The submarine population in the Pacific Rim is growing not diminishing.
Bushranger makes a good argument that the Sierra would have been over-all, a better value.