Sir (did you like that?),
QANTAS management pilots have always attempted to position themselves at the top of the pyramid (regardless of the logics of their propositions - refer B747 at BKK). This accounts for their divergence from the Boeing procedure (in my humble opinion, unjustified)
On the other hand, maybe they have a large number of pilots who do not have the aptitude/skills to select reverse thrust correctly at the appropriate time!! and have to write their procedures accordingly!!
Basically, I cannot understand why egos must interfere with the basic manufacturers' procedures unless dictated by significant local conditions.