I'm sure most average diggers / anchor-wankers / wing-nuts in the lower ranks (and many further up the ranks) are just as patriotic as any Aussie.
BUT.
Every person who swears an oath of office in Australia - military, police, parliamentarians, intelligence services, state governors, city councilors etc - swears that oath to The Queen. Not Australia or it's people or it's constitution.
So, if an incident arose where the government was in conflict with the Australian population, to follow their oath of office, those service members would have to side with the government (and The Crown) against the people. VERY different situation to that in the US. Would be a huge dilemma to the troops on the ground.
I don't think Australia will pan out the same way as The USA - I see pain ahead for Australia before it can be cleansed. The DS here is much more entrenched & much more protected by l;aw than in the US - also the Aussie public isn't even close to being as awake at the US population is fast becoming.