I don't get it. 'Interoperability' with Oz C-130J? In the transport sense I fail to see the advantage. Surely 'just as limited as Oz C-130J' would sum it up better, but that's hardly the underpinning of a robust procurement strategy.
I'm aware that Oz provide NZ with some load design assistance, but this hardly seems a reason to operate the same aging aircraft when the opportunity to modernise was available. Personally, I think not looking more seriously at KC-390 is an opportunity wasted given the capability leap that KC-390 would provide.