Assuming we are on the right track....
By the age of 18, Ernie had acquired sufficient skill to be employed by a circus and taken to WA.
A little research shows Fitzgerald's Circus had a season in WA from May 29th to September 1908 including Perth and Fremantle. They then went on to Adelaide. Wirth’s Circus was in the Eastern States at this time.
Prior to this Fitzgeralds had been in NSW until April 1908
I do not see a visit to WA from it or any other circus in 1909, the year of the "vagabond acrobat" news item.
I see no circus advertised in WA on or near August 16th 1909
By 1910, Ernie was performing in Geelong advertised as "late of Wirth's Circus"
While it could be true he was late of that Company, it seems it was not they who took him to WA.
It was commonly the practice of circuses to train very young children in their crafts while they lived as part of the circus, The children were "adopted" and a deal struck with the parents which promised care and education for the child as well as circus training. They would later join the troupe.
Phillip Wirth was particularly known for this practice.
It made me wonder whether this was how Ernie first learnt his skills. I would suggest it was not from his father, a cook of criminal tendency.

However records show Wirth's Circus was out of Australia from 1893 to 1900.
Sue