I think we shouldn't get hung up on how many first choice Wallabies were playing. If Australia had sufficient and quality depth, they ought to have been able to put Australia "A" (being players not in the first choice 22) on the park and still won.
If I were Robbie Deans, I would not be so worried about the actual losing of the match, but more about the way they lost (4 tries to 2). Samoa were able to shut down the Wallaby backline with relative ease, and only conceded their first try when they were down to 14 players. Even then, they were able to score one when they were still down to 14!!!
It is obvious that once you get deeply into the second choice players, their quality diminishes rapidly in key areas such as the tight, the back row and at 9 and 10. I cannot stress how much Benn Robinson was missed in this game, and will be missed come RWC time. He is the one and only front row forward they have who is capable of giving the Australian scrum anything like parity against the major teams, South Africa, England and New Zealand
IMO, a number of the run on side for this match will now have a red line drawn through their names with a note in the margin "not up to scratch at this level"