The former Argentina hooker, part of a strong Pumas pack at four World Cups, was recruited to add some steel to the Wallabies' set piece, which local pundits fear will crumble against pool rivals England and Wales.
That view gained currency at Twickenham last year when Australia's pack was driven backwards during the 26-17 loss to England.
"Everybody made a big issue about that and the Kiwis and the English will be talking a lot about that," Ledesma told reporters in Sydney on Wednesday.
"We are trying to change perceptions. I think it was much more of a perception. We have to put the scrum in the place it deserves and that is being a really important part of rugby, if not, we will be playing rugby league."
The 42-year-old Ledesma was already familiar to a number of Wallabies players before joining the team, having been scrum coach at Super Rugby side New South Wales Waratahs last season.
The results on the pitch have been mixed but encouraging. The scrum was shaky during the Rugby Championship openers against South Africa and Argentina but stood up well against the world champion All Blacks in the final win in Sydney.
Depth has always been a worry, particularly in the tight five, and the selection of only two specialist hookers in the World Cup squad has been queried.
That one of them, Tatafu Polota-Nau, has been sidelined with concussion-related problems a number of times in recent years has also fanned fears the Wallabies could be exposed in England.
Ledesma said Argentina had selected only two hookers to the four World Cups he played in from 1999 to 2011 and it had never been a problem.
"The facts today are that we have two of the best hookers and I'm really comfortable with it," he said of Australia captain Stephen Moore and Polota-Nau.
"I think that's covered."
