Part of each page will be product-specific, and therefore will be largely the same on each site - even that could be tweaked slightly, for example, emphasising Australian Dollars, New Zealand dollars ...

Other parts may be company specific; they could be rewritten slightly to emphasise the local connection; 'Australia's leading ... '

The 'samey' stuff is only part of the page; SEs will look at the whole page, and are developing particular interest in local content - That may include extra local content, or use of 'local' images and ALT text.

The key is to focus on customer differences, and use that to better focus each site on local needs, which would differentiate the sites as a side effect.

There are other possibilities; does the company actually need two sites? If the products are the same, it may just be the shopping cart stuff that needs to be kept apart - but if distribution is separate, pricing significantly different or local hosting an issue, then keep two sites.