O.P.

Your point is correct but I think your description is technically inaccurate. Tax treaties are irrelevant in this case. (You can claim offsets for countries which do not have a tax treaty).

"Foreign tax credits" no longer exist in Australia taxation law, since 2008. It's been replaced with the foreign tax offset.

VEU pays roughly 5.33% of distributions in foreign withholding tax. You are unable to claim this as a foreign tax offset. With VGS, you should be able to claim this as a foreign tax offset.

This is roughly a 0.197% delta. Averaged across two funds, it's 0.0985%. (There's no non-US foreign tax on VTS).

I've updated OP. Thanks for pointing this out.