Id go with seedings and draw 4 groups split into two sides so 3+1 rounds allowing some blockbusters in the pools, top 2 from each pool go into semis

Say
Group A
England
Samoa
Ireland
PNG

Group B
Australia
Tonga
France
Wales

England play:
3 group teams ie Samoa, Ireland & PNG and top seed from Group B ie Australia.

I'd love to have a strong international game I just don't see it happening I cant understand why France and PNG have gone backwards and it hinders rather than helps stuffing other countries full of Aussies and the problem with the South sea islanders is that any star players go play for New Zealand or Australia then return at the end of there careers

France and PNG have been left behind because of professionalism really kicking in in SL and the NRL. They can't compete with the pro nations of GB/England, Australia and NZ because there are relatively few PNG and French players in SL and the NRL.
As you rightly say the other nations are then packed with second tier Aussies or Englishmen who, despite being 2nd tier, are still regular pro's and so a step above the players that PNG, France or Wales can produce.
However, they also don't help themselves with regular in-fighting at the top of the French and PNG RL.

But the way to strengthen them isn't to condemn the international game to only being 3 teams. It's to strengthen the international game as a whole.

We need much more money flowing from the 2 pro leagues into the international systems, and to significantly strengthen and expand those systems. IIRC the RLEF (European Federation) runs on something like £2-300k a year. That's not really doing anything except the most basic of basic functions (and that's not meant as a criticism of the RLEF) to grow the game in Europe.
We need a properly funded RLEF and a properly funded RLIF, both of which with teeth to organise and oversee international competitions. In Europe we should be concentrating efforts on getting more French and Welsh players into the Championship and SL and ensuring the French and Welsh RL's are properly structured. For instance ensuring Catalans shift from obstructing to actively assisting the French national team.
In Australia they could get a PNG team into the NRL. Fiji seem to have been making strides in recent years, as have Samoa. They should be looking to setup an annual, or at least biennial, Pacific 4 or 5 Nations including Aus & NZ.

Only through actively strengthening the international game and it's structures will it improve significantly.
And whilst we can appeal more to London and other areas in Britain with the domestic game, you're still not going to get many southerners interested in Wakefield v Widnes. In the same way as I couldn't give a toss about Bath v Saracens. It's not relevant to me.
England gets people interested down south, in the same way as they turn up at Twickers but don't for the Union domestic regular games.
We got more (and better) newspaper and media coverage for the 44k at the Olympic Stadium watching England than we did for either the 80k watching the Challenge Cup Final or the 76k watching the Grand Final.

As a sport we HAVE to prioritise the international game. If we don't we won't ever break out of the heartlands and bar a small handful of 4 or 5 clubs, will be forever struggling to keep our heads above water in terms of finances. Sadly the sport bankrupted itself 20-30 years ago after significant periods of chronic under-investment in every aspect of the sport except players wages, we are still dealing with the effects of that terrible period in our sports history.

I imagine Samoa and Tonga would give your team (and most SL sides) quite a game.

Good post

Yes, very well said.