OneWorld Explofrer is generally much more flexible in business class than the Global Explorer fare. On the OWE fare, you can back-track as much as you like within a continent and are not limited to 34,000 miles. The exact same back-tracking rules apply for Global Explorer and OWE - ie no backtracking between continents.

The 34,000 mile Business Class Global Explorer and the Business Class OneWorld Explorer cost exactly the same. But, they will have to return to Australia via Europe and Asia or South Africa, which will take longer and mean more flying.

You can just get to NewYork from Sydney on a 22,000 mile Circle Pacific fare. But cannot include SFO and must return across the north Pacific on AA via NRT. The 26,000 mile Circle Pacific fare will get them to them to where they want to be, and is going to cost similar to the quoted QF/CO fare.