The statement was "Aussie PGs don't really exist in the NBL." and both examples from recent times and over a longer period show that to be plain wrong.
Well, I'd also be disinclined to truly count D-Mac as an Aussie, but in any event I'm not necessarily arguing against your stance, just the particular statistic you used to highlight it.
And yes, there are situations where you can quibble over who the point guard is. Franklin/Heal on the 2003 Kings is another that comes to mind. But as I said in the discussion about Ricky Grace playing the 1 or the 2, it's not like we have netball-style set positions.
Going back over only the modern 40-minute era and expanding to all grand final teams:
2010: Martin (L), McKee (I)
2011: Henare (L), Ubaka (I)
2012: Jackson (I), Martin (L)
2013: Jackson (I), Martin (L)
2014: Martin (L), Ervin (I)
2015: Jackson (I), Wilbekin (I)
2016: Martin (L), Jackson (I)
That's two locals and five imports, assuming I can count.