Yeah I agree, I'd go with the International Studies at RMIT or at least look into it. I found a lot of the subjects I did at Monash felt very broad and rushed. For what you might study in two or three weeks at Monash, you might devote an entire unit to at RMIT. I often wish I did choose this course when I was tossing up between it, UoM and Monash in year 12. You also get to do a semester internship (or study abroad) which imo is great, Monash and Melb have SOME option for interning but it's limited and competitive to get into (at least at Monash).
Whatever, you do, DON'T do the Arts (Global) degree at Monash, because the two core subjects are just really bad and a waste of time. If you decide to go with Monash, just go with the straight Arts degree. You can still major in the same things and study abroad but you'll get to avoid these units.
I can't comment on Melbourne Int studies yet, but they seem to have similar subjects to Monash in second and third year. It will be interesting to see if the subjects at UoM are taught better though.