Why come back to HKG?
At current exchange rates an SFO6 on UK base earns >$95K HKD per month and aussie >$85K HKD per month.
If they wait for a based command, they will get >$122K, >$110K HKD respectively.
So these guys are looking at a pretax pay rise of 3%/12% if they move to HKG and pass their command! I am of course ignoring tax, 13th month, expat benefits, pollution etc.
I think the first 'onshoring' is planned for April 08(UK) and then the rest will follow over a year or two.