by Shirtripper
First off, and this is not a judgement against you, but I've always hated the starting in Australia strategy. I hated it in Classic Risk and I hated it in the early games of Risk Legacy. Luckily in this game you get to change things.Couple of things, you should point out to them they can do to help balance things:
In game wise they could use negative scars to hurt your major cities (assuming that is what you mean by rewards) in Australia. Also if you have a major city in all four parts of Australia that means you lose at least 6 guys taking over three of the territories there. That can slow you down enough but if they found a minor city in Southeast Asian that means you'll lose another man coming out of it. Then add an negative scar their like ammo shortage and things aren't looking so good for your strangle hold down under.
Also if Die Mech have the Fortified HQ starting in Southeast Asian blocks starting in Indo and NG and gives you a tough fight right out of the gate, plus if you over expand and lose too many troops regardless of where you start it will cost you 6 they might be able to build up and pounce on you if you make yourself weak.
Victory wise, if another player wins they could do a number of things to hurt you there, like bringing down the value of the bonus to 1 troop a turn instead of two. They could also found their major city in Southeast Asian and if they start before you, you are cut off from starting in Indo or New guinea. Also whether their is a minor or Major City in Southeast Asian they could fortify it making it even harder for you to get out of Australia.