Talking charts, though, and it is a very different matter. If you are trading PA on AU, it is because you have picked out something that AUD is doing against the USD.... Japan doesnt come into it. Same with UJ. But move to AJ, and you are now looking at their relative movements, and USD is effectively filtered out. USD could go up, down or stay still and you wouldnt care.
So having an AU trade or a UJ trade is fine. But going the same way, in both, is effectively fighting yourself. You might as well have an AJ chart, and be basing your trade on that.
Hope this makes sense. As I said, I am far from eloquent today.
The other main thing to keep in mind is that the US is the dominant mover here, so by going long AU and UJ, you are effectively hoping for USD to simultaneously move up and down
When you have to shoot, shoot. Dont talk.