Clarification....
BKK crew will operate BKK/LHR/LAX/SYD/BKK.
Another group of BKK crew will operate BKK/SYD/LAX/LHR/BKK.
This means a mix and match of BKK and Sydney crews.Also a mix and match of BKK and LHR crews.
All apparently within the overseas base cap.
The kiwi base crew could also be brought into the equation