Maybe they still are our best combination in big games, but IMO they have a limited potential. Barnes is solid, great defense and reasonable game control. Giteau has the odd flash of brilliance but is out of form. Cooper is the only one with the potential to be worlds best. He might not ever get there, but it is worth seeing if he can.
A question: how many of our tries in the June Tests can be credited directly to Cooper, and how many to Giteau?
But the bigger issue is surely this: if by the Ireland Test, we were still getting 'Cooper is confusing us' problems in the Oz back line, and that's after about 4 weeks and 3 prior Tests those backs have been together, what on earth is going on wrt the intensity of back line training, game prep and coaching? Cooper's 'flair and dare' playing style is well know. If he's picked as 10, then it's the task of the whole back line and the coaches to work relentlessly in training to perfect the his relationship with the other backs (and vice versa) and to build attacking and running ploys that build off Cooper's skills but which equally are thoroughly rehearsed over and over again so they are instinctive at game time.
Do we think the ABs brilliant back line awareness, excellent combinations and very low error rate (esp when it counted) on Saturday just came because they are all talented? Yes, talent, but meticulous training and repetitive rehearsal and sound back line coaching are huge parts of it all.
My main point here is that if it's argued 'Cooper is our problem', IMO that's really a case of poor back line training, preparation and coaching being our bigger problem, or maybe the problem.