Let's agree, there's one outcome we want, the second tier nations improving.
So what have been the barriers to that;
1.) Money, both the second tier nations inability to raise domestic revenue and thus tour, and the first team nations tight schedule (and funds) in getting to those nations.
2.) The (second tier) national teams not having enough time together playing high intensity games.
3.) The (second tier) teams having a mix of amatuer and pro players.
No. 3, I believe, can be fixed by No. 2. with some allowances made by No. 1.
NZ and Aus have opened pandora's box with their talks about pulling out of the World Cup. The RWCL and IRB have said that they need the money to support the tournament and the lesser teams. I say let regulated free market capitalism fix this.
We've already seen the Churchill Cup in the NH, England play America and Canada and a few others (Ireland A, Argentina A, NZ Maori, Russia, etc..) There are windows in the regular season for international sides to play. If those windows were also used for A Teams of the first tier teams to play in tournaments against the second tier teams, in the second tier nations' homes, it would allow for their sport to develop, the attraction of getting a scalp against the nominal first tier teams would hopefully drive the second tier nations' (STN) tv audience and gate receipts. I'm sure people would complain it would cost too much, and I'd try to minimise it for the STN by letting them play at home, but for everyone else make it on the proviso that they are allowed to use their full sponsors during the RWC.
If this means cutting the touring sides' games down by one, then so be it. I think most of us are getting sick of watching the same teams swap stadium to play ever spring and autumn, for nothing more than giving the NH teams a confidence boost, or to let the SH teams go on a roll. The domestic game seems to be a much bigger draw for the average fan, with more invested in it. We're just getting bored of each other and it needs a world cup before we all get excited about the national game (3N and 6N Excluded.)