The problem with this question is the word "aussie", implies that they are their own specie. The term Aussie is getting thrown around so much I'd think the Austrailians are almost getting tired of hearing it :lol:
Like zeppelin touched down on, depends on what specie of acan. Where the specie was collected from ie., Australia, or somewhere in the indo-pacific, does not matter. What matters is if it's an echinata, sub-ech, lordhowensis, hillae etc. Two lordhowensis can touch regarless from what region they were collected, the same goes for every coral we encounter in the hobby.
-Justin