Couple of points:
SM4 - i'm not aware of any shifts on West P where we were that short...a couple of shifts where we were one short have happened but nothing too bad. West R is usually the problem staff-wise, but i can't think of any shifts in the last couple of weeks that were particularly short.
direct - 3 applicants for Perth in the end, 2 were submitted after the application period had expired. But even if all 3 are found suitable, they will still have to be released from their current positions.
Really, this is a problem of Perth traffic growing beyond it's procudures and facilities. The West P sectors have screamed for radar (or even ADSB) for years. Traffic is getting busier and busier, and add the summer thunderstorms into the equation and things quicky go pear-shaped. West R has been promised WAARP for so long it's ridiculous. There's no MAESTRO and the flow can't see aircraft until close to 160nm Perth.
This is not to say we don't all need more staff...we damn well DO need more staff....but these problems are not ATC staff related.