World Rugby's eligibility law change – increasing the requirements of foreigners to spend five years rather than three to qualify for their adopted nation – does not kick in until 2021. Anyone who shifted prior to this change is, therefore, free to make a swift change of allegiance.
Christchurch's McNicholl and Halaholo, the Mount Albert Grammar graduate turned Hurricanes' Super Rugby champion, recently inked new club deals to extend their time in Wales, with the ultimate intent of progressing to test rugby.
When Pivac assumes Gatland's post next year, Halaholo appears set to start in the midfield alongside Parkes, a revelation at No 12 for Wales, while McNicholl is equally comfortable at wing or fullback.
"I feel like I've brought my partner over here, we've adapted to the Welsh culture, we've lived here for three years. We've really embraced it," McNicholl, who has scored 27 tries in 59 appearances for Scarlets, said after extending his contract. "I've got a daughter now. She's Welsh, she was born here, she's going to pre-school here and I feel like if I do play for Wales, I'd be doing her and her home nation proud."
No one can begrudge players taking opportunities to progress careers. None of this quartet were ever seriously considered for the All Blacks, either, but this is a clear example of one country exploiting the eligibility loophole to the extreme.
Whether World Rugby has gone far enough in addressing the issue is debatable.
The governing body was certainly slow to act, and on the flipside have shown no appetite to relax rules that would allow athletes with Pacific Island heritage to return to their roots after choosing to represent nations such as Australia, England and New Zealand due to the greater financial incentives often used to help support extended families.
Wales are not alone, of course.
Scotland fielded more foreigners than anyone in the Six Nations; Australian second-five Sam Johnson, South African-born prop WP Nel and New Zealanders Sean Maitland and Simon Berghan among them. Former Hurricanes loose forward Blade Thomson was also named in the squad before suffering concussion.
Ireland have welcomed Bundee Aki, CJ Stander and James Lowe is expected to be one of the last to qualify under the old three-year laws.
Likewise England have benefitted in the cases of Brad Shields, Ben Te'o and Nathan Hughes.
Those in the north often accuse New Zealand of poaching the Pacific nations and while, yes, some players are targeted through scholarships, this argument excludes the vast majority of those whose families move naturally seeking improved life quality through greater opportunities.
Of those All Blacks who featured in the loss to Ireland in Dublin last year, only replacement props Nepo Laulala and Ofa Tu'ungafasi were born outside New Zealand.
Anscombe at least has a genuine connection to Wales with his mother, Tracy, born in Cardiff before moving to New Zealand as a teenager. She also named him after Welsh and Lions legend Gareth Edwards.
Wales, though, face a fight to retain their New Zealand playmaker as English clubs circle during a pay dispute.
Anscombe's stocks have never been higher after he kicked 20 points in a man of the match performance against Ireland to help Wales claim the Grand Slam. Yet, due to a pay band system, he is unhappy about being frozen out of the top salaries in Wales, with these reserved for Lions representatives.
Bath and Harlequins have registered interest in luring the 27-year-old, and Pat Lam's big-spending Bristol are now reported to have tabled an enticing deal worth £500,000 (NZD$964,000) per-season.
The irony is should Anscombe opt for a move to England's Premiership before the World Cup, he would become ineligible for Wales as he does not meet the 60 test threshold for those playing outside the regions.
Anscombe is thought to be on £300,000 to £350,000 in Wales and has been open about his dissatisfaction with the potential £100,000 ($NZD$192,000) difference in earnings compared to some team-mates.
"We all want to play for Wales. There's no doubt about that, but players deserve to be treated well," Anscombe said after Wales won the Grand Slam.
"We're a world-class team. We are doing a hell of a lot for the country, so we should be looked after. I think we've given the Welsh Rugby Union something to be pretty proud about and hopefully the union and the regions can come together and sort out the best deals for the players because that's important.
"At times when they try and pigeon-hole you into something it's a little bit frustrating. I'd love to keep playing for Wales, but we have to work out a few things for sure."
If Anscombe stays, expect him to be one of four New Zealanders in the Welsh backline next year.
