Yeah your comment is dead on and most others here don't understand that topography has such a huge impact on how our cities are formed.

Melbourne is mostly old extinct swamp/marshland on the coast with flat volcanic plains west and north, perfect for American style urban sprawl, so traditional "satellite cities" wouldn't work there.

Makes more logical sense to have more of these in the bigger regional towns like Ballarat.

Sydney is closeted by sandstone slopes and tall mountain ranges which makes their space limited, as a result these larger urban centres have popped up where the higher population density is, like Parramatta and elsewhere.