Defence top brass have been criticised for being top heavy as the numbers of senior commanders increased by more than 30 per cent while the military struggled to recruit soldiers.
"Is our defence strategy to frighten off our adversaries with gold braid? We're going to glint them to death?" Greens Senator David Shoebridge asked military leaders in a testy exchange during a parliamentary hearing on Wednesday.
He accused senior officers of having gone on a "recruitment binge".
But Defence Secretary Greg Moriarty contended, "officers do serious work".
Defence was 4400 people - more than seven per cent - short of its "authorised strength" as of May 1, General Angus Campbell said.
The defence force chief admitted hiring rates were only 66 per cent of this financial year's targets.
"One of our primary challenges, which is relatively unique as an employer, is the medical and psychological screening required," he said.
Citizens of some foreign countries will be able to enlist under a fast-track to citizenship under a new plan by the government to boost recruit numbers.
It came alongside the scrapping of long-range Tomahawk strike missiles from ageing Collins-class submarines as the department looks to save cash.
The decision follows advice from the US that adding the weapons to the vessels was "not viable and does not represent value for money".
The service of the submarines would be extended, with HMAS Farncomb to be the first to undergo the works in 2026.
But defence officials warned there would be "a degree of overrun" on some of the maintenance.
The submarines were "very old boats" operating beyond their scheduled life cycle and risks needed to be managed, deputy secretary Jim McDowell said.
Significant corrosion has been identified.
The six Collins-class submarines were originally slated for retirement from 2026, but will be needed as Australia acquires nuclear-powered submarines under the AUKUS partnership in the early 2030s.
The Virginia-class nuclear-powered boats will be equipped with Tomahawk missiles.
Australia has ordered more than 200 of the potent strike weapons from the US, which have a range of 1500km, to arm the navy's Hobart class destroyers.
