When Darren Lehmann took over as Australian coach in June, he said his top three priorities for the team were to "win, win, win".

With an unassailable three-nil Ashes lead, and the treasured urn back in Australia's keeping after just 14 days of cricket, that mission has been accomplished in a more emphatic fashion than anyone expected when he took charge of a team that was cracked, lacking in confidence and, frankly, not enjoying itself very much.

Last winter, it was no surprise when Australia was beaten by an England team that was experienced and sure of itself.

How did those roles reverse so dramatically, so quickly?

Part of the answer is Mitchell Johnson, who blew England away at the Gabba, and has 23 wickets at 15 for the series. Johnson's selection was a huge gamble, and he might not have played at all had James Pattinson and Mitchell Starc been fit.

It was fitting that he stitched up the series with a short ball at Jimmy Anderson, having tormented the England batsmen from the second day of the series onwards. Once tormented by the Barmy Army for his waywardness, Johnson tearfully acknowledged the Perth crowd as the England supporters sang of wanting to go home.

In truth, this series win has been months in the making. To get better, you have to admit you have a problem, and Australian cricket fronted up to its problems once after the four-nil disaster in India, and again after cascading to an embarrassing defeat at Lord's in the second Test in England. That was rock-bottom, and both Lehmann and Michael Clarke have spoken of the gains made in the next three Tests.

The weather gods ruined things in Manchester, while lack of belief and a game-changing spell from Stuart Broad did for Australia in Durham.

Even before England, some building blocks were in place. Brad Haddin, then 35, had been pensioned off by everyone, including the selectors, but they glimpsed a need for a tough, professional, resilient cricketer who could take some pressure off Clarke, and whose form had flourished since an enforced break to be with his seriously ill daughter. With 325 runs at 65 in the first three Tests, Haddin's recall as vice-captain has been a masterstroke, not to mention his brilliant catching behind the stumps.

The only batsman who has scored more heavily than Haddin in this Ashes is David Warner, who has had to confront his own problems in the aftermath of the infamous bar-room stoush with Joe Root before the last Ashes.

While Lehmann presented Warner with a clean slate, he is said to have conveyed to him that another major transgression would not be a good career move. Warner was told to make runs, a mountain of them, to make sure of his Test spot and the results were game-changing centuries in Brisbane and Perth, and another nipped in the bud by a declaration in Adelaide.

With an enforcer at the top of the order – Warner – and with the new ball - Johnson - and the others have been able to play their roles.

Clarke continued his masterful run scoring and the relentlessness of Johnson, Ryan Harris and Peter Siddle, even in the searing Western Australian heat, collided with the incompetence of England's batting. This is not a vastly different team from the one that lost three-nil in England, and with the exception of Warner and Steve Smith it is not a team for the future, but none of that matters to the architects of Australia's Ashes revival.