The pair often eyeball their competition around the family dinner table.
Team Wells, consisting of brothers Jossi, Byron, Beau-James and Jackson, are a perennial on the New Zealand ski scene. Team Porteous - Nico and Miguel - are gaining traction.
All six will be in contention for PyeongChang Olympic places in February, barring injury.
Snow Sports New Zealand and the Olympic Committee hope to cement most selections before Christmas to maximise preparation time. The official cut-off is January 24, 16 days before the Games.
An indication of athletes' readiness will come at the biennial Winter Games unfolding across Queenstown, the Lakes District and Central Otago in the next fortnight.
Jossi Wells finished fourth at the Sochi Olympics in the halfpipe and 11th in slopestyle. This time he's concentrating on slopestyle in pursuit of the country's second Winter Olympics medal.
The first was secured by Annelise Coberger in slalom at Albertville in 1992.
Wells won Winter X-Games gold last year at Aspen, but ruptured his patella tendon nine weeks ago, an incident he describes as a "hiccup" on the path to PyeongChang. He has already met the Olympic selection criteria.
"I might get a [Olympic] spot, but if I'm not skiing well before the Games, and one of my brothers or another New Zealand rider is, they might get sent instead. It's quite cut-throat.
"I'll get back on the skis in November and should be jumping in December. That'll give me a six-week window to get my game together.
"It [the injury] comes with the territory," he laughs. "You pay in blood or snapped tendons.
Porteous has graced ski slopes from six-months-old in his mum's backpack amid the French Alps. He started skiing aged four.
At 15, he is already contracted to work with Red Bull New Zealand and a year ago, became the world's youngest skier to land a "triple cork 1440". For those unfamiliar with that term, imagine what you might look like if placed into a live tumble dryer for four seconds ... and add a dignified landing.
"I wouldn't say I've mastered it," Porteous says. "I've done it twice - that's how far the sport's come that it's not really a special trick any more. Now everyone's doing it.
"But that's the sport. It's not just about winning, it's also about pushing yourself to the limit."
Add the need for commercial savvy. Porteous' signing with an energy drink conglomerate and Wells courting a portfolio of sponsors are examples.
When companies find a sports entity that fits their brand, the equation ends in what marketing gurus might describe as "win-win".
At 27, Wells has followed the snow for what he describes as "over 10 years" and earned a successful living.
"It comes down to people enjoying what you do and wanting to watch what you do.
"Take Roger Federer. If you watch him play tennis and enjoy his interviews you might think 'Federer's a good dude, I'm into this guy and I'm going to back him'.
"Being a professional sportsperson, you have to conduct yourself a certain way and social media plays such a big role these days. It's super important to have relevant content coming through.
"With sponsors, you tend to have year-long endorsements. That means wearing their product on the hill, having their logo in place during interviews and posting up photos in their gear.
"It's a lot more than just doing a triple cork 1440."
Wells knows skiing tends to be "a young person's game" and accepts that could mean a limited shelf life.
"Tricks get harder, because more people can perfect them. It's human instinct to keep progressing.
"Now footage is so accessible via social media, more kids are hungry to get into the industry. That makes it competitive."
Both athletes grew up in circumstances requiring a mixture of correspondence and home schooling.
"It's hard being on the road as a top athlete and try to finish NCEA," Wells says. "But if you're a smart man, and I know Nico is, you accept skiing's not going to last forever.
"As long as you have good parents around to instill that, you'll get it done.
"For me, it was a case of 'if I don't get it done tonight, I won't be skiing tomorrow'."
"I do school year-round," Porteous adds. "I don't have a full holiday, because otherwise it's too hard to manage.
"Mum and Dad help out a lot. It's hard to keep up, but you have to find a way and prioritise things."
The pair have tested out the Games' Bokwang snow park. Porteous finished eighth at a qualification event six months ago.
"It was by far the best event of any I've experienced this year - really organised, good weather, friendly people and the best pipe of the season. It couldn't be a better environment."
Wells finished third at a World Cup event in February 2016.
"The slopestyle course was amazing, really creative, and as long as that stays top notch, we can compete to the best of our ability.
"You just have to be supremely confident when you drop in. Your job as an athlete is to make the judge's job as easy as possible."
As well as beating your brothers - and the world - in the process.
