Mewkus: All of those funds have a HUGE home bias. 19% in Australian shares when the Australian economy makes up only 2% of global GDP ($1.5tn of $72.6tn) is crazy. You should investat most5% in Australian stocks, as a small(!) home bias is justified by the currency exchange risk resulting from investments abroad. At the same time, if the Australian economy tanks, you're also more likely to lose your job -- at the same time as the value of your portfolio crashes. So there's some argument that you should not overweight at all. In practice, it doesn't make a huge difference, unless your overweighting 25-fold (as in the Topaz plan). It's actually worse than 25-fold if you look at just stocks, where 77% of them are invested in Australia. That overweights nearly 40-fold.
As for Spartan vs. VTSMX: they don't track the same index, so you wouldn't expect them to have the same return. The former invests in mid-cap firms (e.g. no Apple, Google), the latter invests in the whole market. If you buy into index investing as a philosophy (e.g. you can't predict which segments will do better in the future), then you'll want VTSMX. If you think mid-cap firms will do better than small-caps and large-caps, then you stick with Spartan.
Personally, I'm invested 50% in VTSMX and 50% in VGTSX, which is the total international stock index (or rather their ETF equivalents, as I'm holding them in taxable accounts). The US economy makes up about half of global GDP, while VGTSX covers (roughly) a representative sample of stocks of the remaining half of the world. That is, effectively, what a global stock index fund should look like under the assumption that you do not want to overweight or underweight any part of the world and any particular sector.
To reduce risk, if desired, you could add the VBMFX, which is the total bond market index, and the fairly new VTIBX (the international version of that). Bond markets outside of the US aren't quite as mature, especially for corporate bonds, so you probably want more US bonds than international... but I have no idea what a reasonable allocation would be for that, as I don't invest in them myself. if I had to ballpark it, I'd say 3:1 for US bonds. So, for example, a portfolio could look like: 40% VTSMX, 40% VGTSX, 15% VBMFX, 5% VTIBX. Who knows how much better you do than if you just had 20% in VBMFX and dropped international bonds... there's a reason the latter indices are pretty new and seem kinda small. For Vanguard, for example, VTIBX holds $32bn, compared to $141bn for the US-equivalent.