Reading the Dick Smith page, they say goods would be covered by their custom charter which in my reading gives you warranty-level right of free repair for 2 years on goods over $500. Buying from Amazon would involve the complications of shipping back to the States for any repair. Not a trivial consideration especially given that Pixels have not had a glowing reputation for reliability. I am pretty tempted by the 4a. I need to replace my Sammy S5 and I dont want a phone that is any bigger. Getting anything under 6" that isnt junk or an Apple is tough. Also tempted by Apple but not that keen on being locked into Apple ecosystem. Only other option is last year's 10e so far as I can see.
I think we're on the edge of a few smaller phones being released. Samsung hasn't announced their latest range with a mini version, but I wouldn't be surprised to see one turn up later. I vaguely recall reading one of the up and coming type brands might be releasing one as well.
The Pixel 5 is also not too large, but more expensive than the 4a. I'm still really liking the 4a - compact, fast, good enough all round that I don't need a flagship.