Terminology, Bloggs!
Back in the olden days the top job was CDFS, the Chief of the Defence Force STAFF.
Since the job became CDF a few years back, Angus is the first blue-suiter.
And one of my fellow 21 Academy Course-mates, AVM Roxley McLennan, is looking good to step into the CAF slot. But AVM Geoff ShepShepShepherd (those who know him will understand this) is also a contender.