there have always been some very good junior rugby players in victoria, even in my day (late 60's - early 70's). until the rebels there has been only one option if you wanted to "kick on" as a rugby player, that was to go interstate.
originally that meant Queensland usually, later on the ACT.
now the young kids, increasingly of PI heritage, are able to stay in victoria and pursue a pathway. numerically there will always be 5 to 6 good players in NSW/Qld to every one in Victoria, but hey you can only play 15 at a time, luckily.