A New Zealander and an Englishman are with Wales, Irish forwards are apparently raving about the South African in their camp, another Kiwi is a key part of the Scottish brains trust and an Australian who played for Ireland is pulling the strings with England.
Countries get the coaches they need from wherever they want, so prepare for news of another person crossing boundaries - an Englishman could be about to help Australia with their scrum problems.
Remember Trevor Woodman, the loosehead prop who with his then Gloucester club-mate Phil Vickery pushed Australia all over Sydney - when they were allowed to - in the 2003 World Cup final? Well he's being working very successfully for a couple of years with Sydney University, and friends say the Wallabies have taken notice. The Australian scrum is still a work in progress and word is that feelers have been put out in Woodman's direction.
That's right, a work in progress. There's been an awful lot written about the Australian scrum, much of it based on memories of what happened at Twickenham in 2005 and in Marseille in last year's World Cup. However, things have moved on, as anyone who watched the recent Tri-Nations will know.
Throughout the series, and then in the Bledisloe Cup game in Hong Kong a couple of weeks ago, Australia often opted to scrum penalties close to the New Zealand line. You don't do that if you have big doubts about your front five. The All Black scrum might not be the same without Carl Hayman to anchor it, but the likes of Tony Woodcock, Neemia Tialata and Keven Mealamu are no pushovers.
Sometimes that confidence wasn't entirely warranted, but the Australian scrum has moved on since Robbie Deans - another Kiwi - crossed the Tasman. A quick look at tomorrow's team sheet shows that the coach has added the weight of Hugh McMeniman to the starting pack and has a couple of big options waiting on the bench.
You would expect nothing less because, as Martin Johnson knows and Delon Armitage is about to find out, no country is more meticulous in its planning. Deans probably knew little or nothing about England's new full-back a week ago, but you can bet Australia will have done their homework now.
They will have watched Armitage's assured performance against the Pacific Islanders over and over, noting every mannerism or repeated action, and then gone to the library for footage of him playing for London Irish at full-back and centre. By tomorrow Matt Giteau will have been spoon-fed an attack plan and once the whistle goes he'll add flourishes of his own from fly-half.
Coaches want their full-backs to be good under the high ball, to have pace, and to then be a threat with ball in hand. Against a second-tier side Armitage looked the business. If he comes out as well tomorrow, England can begin believe their selection difficulties at full-back are over at last.
It won't be easy because Australia seem able to produce an endless stream of guys who kick or catch well, often both. Perhaps it's their Aussie Rules background, but it's becoming an increasingly valuable attribute as stats show the increasing influence of the kicking game in Test rugby. For instance, 50% of New Zealand's tries come from kicks - more last week against Scotland. They kick to score, either with little chips, cross-kicks for big men out wide or grubbers that set up one-on-one foot races. Either that or they go deep and wait for mistakes and that was where Scotland committed suicide.
Ireland will be more of a handful because I expect them to be back to somewhere close to pre-World Cup standards at Croke Park tomorrow. Graham Henry obviously feels the same because he's fielding the best All Black XV he has available.
Word from the Irish camp is that Declan Kidney, the new head coach, has recruited well and that the players are responding to his new staff, including Gert Smal, the South African forwards coach. After a bad Six Nations Ireland's is a happy camp again, especially for those Munster men who, for once, have been close to home and families with base camps in Limerick or Cork.
These things matter, especially if the game is tight, and I expect it to be no more than five points either way. England should beat Australia. Sorry, Scotland - it's South Africa for that one.