At some time in the future CWE had to address different types of...

At some time in the future CWE had to address different types of foundations. Pyles are not suited to all types of ocean floor. The anchoring system will be different for say sand, mud, shale, rock etc.
Western Australia is home to some of the world's largest off shore oil and gas projects.
I believe CWE have been smart in tapping into knowledge and funds that are available on their door step. The site when selected may be no different to CETO 5 site. The thing is they now have access to information on a huge variety of sea bed floor characteristics.

The offshore industry has learnt to use the sea to their advantage, be it lifting or anchoring.
A series of water filled bladders can be used 1,000 liters is 1 tonne in weight. Twenty tonne bladders have been used for decades in the transport industry. One instance that I remember was Carlton and United Breweries transported concentrated beer from Melbourne to Ballarat where water was added at the Ballarat Brewery to saved on freight.
If they use bladders they can be made to any size cheaper and installed faster than pyles.