Gulf
As you say the NAA's will decide on augmentation, in the case of the UK it's being left "as is" and i suspect that will be the case in most countries (unless you can give real specifics). In my humble view a look is required at the UK rule that allows a third pilot to be added to the crew to avoid "factoring" (which is different to augmenting). The 3rd Pilot does nothing at all, and most Long Haul Pilots I know deem it a waste of time. The other minor issue is UK rules allow in certain circumstances a non-acclimatised crew to have a longer FDP than a acclimatised crew!