Dick,
Most on here are also amazed that the figures used for the Broome/Karattha (one day I'll learn how to spell Karratha??) decision are not available ...that's what has caused all the rucus. At present, we're all relying on our own particular questimates.
However, unlike yourself, I would like to see the specific volume figures for the proposed link airspace ... not the US or Mongolian general figures for Class E airspace. That's of little use.
I want to see what the boffins calculate will be the chance of a prang in Broome Class E link Airspace. A comparison with C or D ( in the same volume) would then be worthwhile.