But nobody is suggesting that a single one-off friendly is the aim for us either. The argument is that we should have central contracts so we can play 3,4,5 games.

Super Rugby starts in February and ends in August, Premiership RU starts in September and finishes in May. The seasons only overlap for about 10 weeks.

Sadly mid-season or post-season hasnt really made much of a difference

Fine, create a window if you want.

Why hold ourselves to a higher standard then everyone else?

Samoa, Fiji, PNG, France, NZ, Wales, Scotland, Tonga,
maybe
US, Italy, Cooks Islands, Ireland,

I'd try and sort out eligibility first. Persuade Australia and new that in the interests of the international game that they don't pick islanders, and in turn improve those sides. not sure how we could get stronger northern hemisphere teams without clubs from those countries playing at a higher level

Agree with this in general.

But I'd say I think the way (or at least part of it) to achieve this is by having more internationals on a set calendar. So then, say, PNG or Fiji would have more chance of keeping "their" players if they knew they were going to get so many games a year, every year, including against top teams, to build around.

As for NH teams, again I agree on the clubs which is why I'd focus every ounce of effort and every penny on France and Wales. They have clubs, maybe not at the level we'd like but it puts them a step ahead of the other nations. Again, having a set international calendar guaranteeing say 5 or 6 internationals a year I think is vital. But there's also plenty more work can be done to setup/strengthen the infrastructure for these national teams too. At the moment the infrastructure for internationals is very weak.