Though culture shocks are inevitably part of professional rugby's rapid development, nothing in Britain has ever matched the exhausting regimes inflicted on Saracens and Northampton of late.
Their meeting today brings together two Kiwi coaches, the Waynes Shelford and Smith, whose dawn squad sessions, withering post-match analyses and ruthless selections are suddenly the norm at both clubs. So much so that men of the calibre of Kyran Bracken and Thomas Castaignède occupy the Saracens bench today. Their only consolation is the chance to eavesdrop on the touchline duel between one of coaching's sharpest cookies and perhaps the sport's most irresistible force.
For if Smith, the former All Black fly-half and coach now at Northampton, is globally respected, "Buck" Shelford is a legend. Saracens' England prop David Flatman could hardly wait to inquire about the infamous "Battle of Nantes" between France and New Zealand in 1986 when Shelford played on despite a ripped scrotum. "I had to ask him if it was true. He just said: 'Yeah, mate.'"
As All Black captain between 1987 and 1990, Shelford never lost a game. Listening to him this week, it is not hard to understand why.
In his opinion, for instance, every player plying his trade in the Zurich Premiership should count his blessings. "Are they lucky to be getting paid as much as they do? Shit, yeah! The average starting rate for an All Black is £40-45,000. There are junior players in this club who are getting more than that. If you never rose above Super 12 level, guess how much you'd get? Around £25,000. In this part of the world they're overpaid for what they do."
OK, Wayne, how many Premiership sides would hold their own in the Super 12? "Maybe Leicester, on last year's form, but no one else. I'd equate the Premiership more to the NPC in New Zealand and some of the clubs here would probably be at the bottom of that." Beneath his ever-present baseball cap his eyes are sparkling. Shelford is clearly a man who still relishes a scrap.
Which is just as well, for the patience of Saracens' owner Nigel Wray is wearing thin after last week's 50-point drubbing at Wasps. Wray describes this season as a "defining" one for his investment, adding pointedly this week: "You cannot go on financing failure." Shelford, though, has inherited a squad he believes is still laden with self-doubt and estimates it will take two seasons to build a side in his own formidable image.
To get there he will draw on a decade of coaching experience at both North Harbour, his old province, and Italy - and his time as a PE instructor in the New Zealand navy. Instead of driving he regularly used to run 12km to work each day, conduct classes, train at lunchtime, go rugby training in the afternoon and then cycle home afterwards. This appetite for "hard yakka" has never left him, and his players still wince at the memory of their pre-season military-style camp in Aldershot.
The harsh regime included allowing the players a few beers one evening, only to drag them from their beds in the dead of night for more punishment.
"These guys have not been tested mentally," shrugs Shelford, who even insisted on exposing his two sons, 17-year-old Eru and 15-year-old Mitchell, to the same torture.
"You talk to Kyran or Richard Hill and it was the hardest thing they've ever done in their lives. Some of the guys almost cracked but that's what it's for . . . it's about how far the mind will allow them to go." What about his sons? "I just wanted to see what they were made of."
That single line could serve as a perfect epitaph for the bullish yet sociable 44-year-old Shelford. But he still has ambitions to coach the full All Black side and he retains complete faith in his methods.
"I don't tend to offer them the stick or the carrot. I just keep saying: 'Do you want to be a gold medallist? What are you aiming for?' If a guy says he'd be happy to finish third, I reply: 'So you're calling yourself a loser already.' Why settle for second best when you can be a winner? A lot of these guys are playing 30-40% below their potential and a lot of that is down to self-doubt. The mind is a powerful thing."
He also defends his increasingly controversial selections - "This is going to be a long season . . . you can't just play the same team every week because they'll be flogged by Christmas" - and sticks by his belief that a good healing session in the pub - "It's not going to hurt you" - is no bad thing for a professional sports team. Far worse, in Shelford's eyes, is the teetotal star who loses sight of his priorities. "Everyone's got an ego but if you don't deliver on the field those egos have to be smashed."
Neither will weak-minded, slow-developing young professionals last long, and Saracens under Shelford should improve once their French prop Christian Califano is finally fit.
"I've played with him often enough to understand the impact he has," admits Smith, still shaping the Saints, for whom Shelford played from 1990-93, to his specifications. "You might beat him but you never get on top of him. Having said that, aura doesn't always win rugby matches." We shall find out this afternoon.
