Why those three? You've omitted two out of three of the schools (USyd, UQ) with the most int'l student grads, which is fine, but intriguing.
You won't find meaningful rankings in terms of education quality (which would rely on comparative outcomes, and possibly incorporating admissions standards), as Australians don't publish such rankings here per se, having long had a culture of egalitarianism in education. There also just isn't the history of students ranking schools -- it's only been in the past 10 years or so that there's been schools beyond the traditional, regional public unis, which most would consider on par with each other.
Helping in *some* regard (as a very basic proxy) might be basic admissions criteria and GPA/exam cutoffs, available in the ACER admissions guide, here:
http://gamsat.acer.edu.au/index.php?option=com_content&task=view&id=22&Itemid=281
Maybe with all the new medical schools [approximately doubling in number] since then, and who must compete for international dollars, the culture will start to change, but so far not in any standardized or objective manner. There is *some* prejudice here against the newer (non-traditional) universities, similar to how there had been a prejudice against the previously new grad programs (starting with Flinder, in 1996) with many ill-informed believing that grad was for inferior students who couldn't get into undergrad programs (which prejudice has reduced over the years as Australians become more accepting, and take advantage, of being able to explore other academic opportunities and pre-professional interests beyond what they had earlier been required to virtually set in stone while in high school; and as more of the traditional schools themselves become graduate).
For those who care about overall international reputation of their future alma mater, a standardized (not to be confused with necessarily accurate) ranking is done by the Times Higher Education in the UK. In their lists, the following schools rank in the top 50 of the world for reputation in the category of Life Sciences and Biomedicine (and I'd argue should therefore be considered approximately equivalent
by that standard):
(
http://www.timeshighereducation.co.uk/hybrid.asp?typeCode=423)
UMelbourne
USyd
ANU
Monash
UQ
UNSW
Note however that the THE survey methodology is contentious (along the lines of wtf does reputation mean, how do we measure it, and what does it imply about quality of education?). For those who care merely about straight-forward measures of research quality (and whatever that implies to them), I'd recommend the Leiden Ranking from the Netherlands. They rank schools in terms of a variety of publication stats (looking at 700 publications). Below are the Australian unis in the top 250 of the following categories:
(
http://www.cwts.nl/ranking/LeidenRankingWebSite.html)
Total # of Publications (rank):
USyd (52)
Melb (58)
UQ (73)
UNSW (107)
Monash (138)
ANU (151)
UWA (180)
Adelaide (230)
Normalized by uni size (rank):
ANU (120)
Melb (154)
UQ (159)
UNSW (163)
USyd (175)
UWA (187)
Monash (192)
Adelaide (214)
Citations per Publication, a useful measure of "impact" (rank):
Melbourne (149)
ANU (166)
UQ (175)
UWA (181)
USyd (182)
Monash (194)
Adelaide (204)
Note that pretty much the same schools pop up, just in different orders. Of course, these are gross measures and not specific to medicine.
-----------------------------
As to C12's list of three...
ANU is a highly regarded university overall internationally based on such things as research dollars and publications (as reflected above). However, generally speaking, Australian unis don't have the research emphasis and tradition of American, or even the bigger Canadian, schools. Moreover, it's tenuous to extend research prowess to quality of medical education -- unless you intend to pursue a research career (some will argue with this, but I think you'll find a general consensus outside the US). As you've noted, ANU is also *relatively* new at teaching medicine, which doesn't say much in terms of education quality, but it does mean the school has no meaningful track record of placing Canadians back home.
Monash, also a top Australian research uni (by publication measures and "reputation" at least), was traditionally an undergrad (in the N. American sense) medical school, taking only students out of high school. For a few (three I think) years, it's had a graduate campus (Gippsland), which has only somewhere around 5 int'l students per year, who have not yet graduated.
Flinders of the three has had the longest track record (time wise) of taking, graduating and placing Canadian students. In this sense, it has a top reputation back in Canadia. It was the first Australian school to become a graduate program (1996), in no small part in order to cater to N. Americans when it was financially strapped. USyd and UQ followed suit within the next couple of years and now have the largest int'l cohorts (incoming and graduating). I don't think you'll find any substantiated claims that any of these three has a superior placement record for its Canadian grads, because schools don't publish such information. In terms of hearsay, students place well and there hasn't been any discrepancy amongst them worth noting, and no scandals (yet) of droves not getting back to Canada.
Note that there are many other grad options, and I'll mention Melbourne's spanking new program in particular merely because the uni in general is internationally highly regarded, it does a lot of research, and the med school itself at least *had* the reputation of being the most difficult to get into (when it was undergrad).
You can certainly ask individual schools what their placement stats are, but I think most won't give you an answer beyond anecdotal ("...We've placed students at x, y and z"). Flinders (Tony Edwards) will likely be the most upfront and may give actual stats, and UQ is starting to head in that direction, but this is just the very beginning of what I see as an important marketing trend that's yet to catch on.
Other important questions to ask, in order to get some proxy measure for what you're asking (and which will also help push the reporting trend along) are: 1) what are the USMLE score of their American students (schools are now required to collect this data in order to keep their American students eligible for Stafford loans); 2) what support is available to help their N. American students do well on their professional exams; and 3) how do they help facilitate N. American clinical rotations, which are important in order to get placed back home.
That's it, I'm out of initial thoughts.