by sklar
Although it isn't quite the same game, in my "Galactic Risk" variant (which can be found in the files section), I suggest having one landing zone per continent on Earth, like other planets/moons/etc. The two variants are similar, so this could work for you.The ones I suggest are Nunavut – Argentina – Warsaw Rep. – Zaire Military Zone – Alden – Oz Testing Ground. As much as possible, I tried to select territories that are in the middle of their continent (which kind of making it a pain to defend against...).
Hope this helps!
(edited to add: Also, I somewhat disagree about Australia being isolated without a landing site. There is still all the water territories that lead in, making it much more open than classic Risk).