For decades, there was an understood hierarchy in men's rugby league that went something like: Australia, New Zealand, England, a bit of daylight, then everyone else.

That was borne out in the international results, with the Kangaroos, Kiwis or Brits the only teams to feature in World Cup finals from 1970 to 2017. Australia, England and New Zealand are currently the only federations in International Rugby League's Tier 1.

They remain the only teams to be crowned men's or women's world champions — Australia winning 15 times, New Zealand on four occasions, and Great Britain three times, but not since 1972.

But, when Andrew Fifita and Jason Taumalolo opted to turn out for the Mate Ma'a more than half a decade ago, the course of international rugby league changed.

A burst of pride and power was injected into the Pacific nations, with Tonga and Samoa the most immediate beneficiaries.

It culminated in Tonga going within three points of reaching the 2017 World Cup final, followed by a famous win over Australia at Eden Park in 2019, and was hammered home when Samoa went all the way to the World Cup final in 2022.

We saw it again this year as Tonga threatened Australia in the Pacific Championships opener, beat New Zealand in a thriller, and came within a converted try of the Kangaroos in the final on Sunday afternoon.

The side that lost the men's decider 20-14 was littered with world-class talent like Addin Fonua-Blake, Taumalolo and Eli Katoa. But also scattered through the side were four State of Origin players — Haumole Olakau'atu, Keaon Koloamatangi, Felise Kaufusi and Daniel Tupou.

When Samoa reached the final of the World Cup in 2022, there were nine players who had (or have since) played Origin in the line-up.

It's a benefit not afforded to the likes of England New Zealand.

Victor Radley bid farewell to his Origin chances when he pledged allegiance to England, the country of his father's birth, for the World Cup in 2022.

But Tino Fa'asuamaleaui and Payne Haas could commit to Samoa while still turning out for the Maroons and Blues, and New Zealand-born former Kangaroo Kaufusi can play for Queensland and Tonga in the same year without having to make a difficult choice.

While it's an undeniable boon to Origin and the international game, and no sensible person will bemoan 12-time world champions Australia losing players to the Pacific Islands, there is a risk of an uneven playing ground for New Zealand in particular.

"New Zealand are worried about that," International Rugby League (IRL) chairman Troy Grant told ABC Sport.

"The challenge for New Zealand is to continue to work in-country to make sure those who are just Kiwi eligible are plentiful and of the quality to play."

When Tonga made its first run to the World Cup semifinals back in 2017 (when Fiji also beat New Zealand to reach the final four) they did so on the back of Taumalolo and a slew of other former Kiwis.

Taumalolo made his international debut for Tonga back in 2013 after 20-odd NRL appearances and played in that year's World Cup for the Mate Ma'a, who failed to get out of the group stage.

Once his career hit its stride the following year, Taumalolo switched to New Zealand, the country of his birth, for perhaps the best years of his career before eventually changing back to Tonga.

It's a common pathway — James Tedesco and Mitchell Moses played for Italy and Lebanon before earning their Australian caps, and Xavier Coates copped flak for doing something similar when he jumped from Papua New Guinea to the Kangaroos.

Players are coming up in a world now where the assumption is no longer that playing for New Zealand, Australia or England are the only paths to a World Cup final.

Isaiya Katoa was born and raised in New Zealand and moved to Australia before he was a teenager but, like more than 80,000 people living across the ditch according to the last census, he identifies as Tongan. He could have played for the Kiwis, but the 20-year-old has instead become the latest game-changer for Tonga while New Zealand had to call Shaun Johnson out of retirement to play in the Pacific Championships.

And who could blame him? Where's the incentive to play for New Zealand if a player's connection is as strong to another Pasifika nation, they are just as much of a force at major events, and you can retain the chance to play Origin?

"There are those that have dual and sometimes eligibility for four or five nations because of their family heritage and history," Grant said.

"That's the way I think is healthy for us that we have that ability for heritage to be recognised because there is a strong link.

"The system as it is now has obviously helped a lot because the Samoan and Tongan boys who get that Origin experience … and elect to play for their heritage nations, rather than the Kangaroos, lifts the standards and raises the competitiveness, and international rugby league is a winner as a result.

"Long term, New Zealand do have to guard against that. They are conscious of that and we do talk to them, but they were the [Pacific] champions last year. So that's the wonderful thing about how competitive it is."

There are benefits in terms of finances and influence for the countries' governing bodies, but when the top teams are the best they've ever been, that may not be enough to push players to give up the chance to play Origin and represent your family.

Will Tonga and Samoa become Tier 1 teams?

It doesn't look likely any time soon, according to Grant.

The IRL tier system isn't just about on-field results or elite player quality — Scotland and Ireland were in the top tier until the last annual audit. It's about the quality of domestic competition, junior pathways and participation in the spot in those countries.

Both Samoa and Tonga face difficulties on that front, not least of which boils down to population.

About 220,000 people live in Samoa and just a tick over 100,000 in Tonga; half of which are under 25, as many people leave the Pacific nations to seek employment abroad.

Tonga National Rugby League was also expelled from the IRL in 2020, and only this year did Tonga Rugby League XIII, led by Parliament Speaker Lord Fakafanua, regain control as the official governing body in the country. And Samoa has a "brand new" governing body that came in two years ago around their run to the 2022 World Cup final.

"They've got some legacy issues to overcome, but they're well on the way to becoming a force to be reckoned with in the future," Grant said.

He admitted it could be difficult economically for smaller island nations to establish the sort of domestic pathways required to be considered Tier 1 teams, but the current system is working a treat for them.

The ability for the stars like Jarome Luai, Stephen Crichton, David Fifita and Olakau'atu to turn out for Samoa and Tonga without having to forego Origin eligibility will make the interstate showpiece and the 2026 World Cup infinitely more competitive and entertaining events.

"The competition's getting levelled out," Grant said, adding the women's game will see a similar shift as the NRLW grows.

"The big gap the Jillaroos have on just about everyone at the moment will close in time, and that's only good for the game.

"It could be the strongest Samoan, Tongan and Fijian teams you've ever seen before. Who knows what's going to happen?"

But if the balance of power continues to tilt away from the 'Big Three' of Australia, New Zealand and England, the conversation in 2030 could have a very different tone.