I've put this idea before.
It would even out the comp, and if you are worried they would both make the final, put them both on the same side of the draw so it couldn't happen.
If international league is always going to be a joke because Australia is too strong, do something about it, and NSW and Qld are already sides with a massive profile and following.
The only time Aus should play is against GB and NZ is in tri-nations.
GB already splits into several sides. It would be nice to find a way to split NZ into two as well.
We would very quickly have a tournament with a dozen credible teams.