If 'o is required before ia as a subject, why not for au (and 'oe)?
Is Hawaiian a VSO language like Tagalog?
Wikipedia says: "Hawaiian is a predominantly verb–subject–object language. However, word order is flexible, and the emphatic word can be placed first in the sentence." There seem to be one or two other exceptions too.
Both Hawaiian and Tagalog are Austronesian languages just like Samoan and Maori and many more, and most of them have similar structure to some extent.
That's cool. Check out this video of a Māori guy learning Indonesian talking about the similarities that surprised him.