French club rugby is not noted for the presence of non-French coaches, yet while Bernard Jackman coaches Grenoble in the Top 14, this weekend's opening round of the ProD2 finds Eddie O'Sullivan's Biarritz at home to Jeremy Davidson's Aurillac on Sunday (kick-off 5.30pm Irish time and live on Eurosport). Thus, there are more Irish head coaches in the ProD2 than there are in the Pro12.

For O’Sullivan it will be his first competitive outing with his new employers, whereas for Davidson, who also served time as a forwards coach at Castres, it will be the start of his third season as general manager/head coach et al with Aurillac, where his stunning work saw them reach the play-offs two seasons ago with the division’s 14th largest budget.

That has increased from €3.65 million to €4.36 million (and 12th in the ProD2 rich list) this season, and there’s also been a €6.7 million redevelopment of Aurillac’s Stade Jean Alric. This is another factor to consider as Davidson weighs up the offer of a five-year extension despite two years of his current contract remaining after narrowly missing out on the Clermont forwards’ job to Jonno Gibbes.

“I haven’t signed it yet because I didn’t think there was any rush,” says Davidson. “This is my fourth year here and getting to the semi-finals two years ago with the 14th highest budget was an amazing achievement. I would love to work in the Top 14 again but sometimes you’re better off being the man in charge, doing things the way you like and being comfortable in your job and your surroundings.”

While he mulls over that (and his native Ulster mull over filling their head coach vacancy in the long-term) Davidson is keen to welcome O'Sullivan to the French second tier. "I'm looking forward to seeing him. I left him a message when he was appointed to wish him all the best," said Davidson, who won the last of his 32 Irish caps under Warren Gatland before his ever-worsening knees forced him to retire in 2003, and as such was never picked by O'Sullivan.

"It's a dog-eat-dog league. Any team can beat any other team with home advantage, especially with the refereeing. I've seen a few escorted off pitches. There are usually lots of upsets for bigger teams away from home," says Davidson, who draws heavily from the club's academy while recruiting judiciously, including the ex-Ulster pair of hooker Nigel Brady and winger Connor Gaston, and ex-Munster lock Brian Hayes.

Comparatively marooned in the Auvergne not far from big brother Clermont, Aurillac finished 11th and fully 29 points adrift of the top five last season, but Davidson reasons: “Every year we aim for the top five because whenever you get into the top five there’s a chance (of promotion). But realistically if you get above your budget in this league then you’ve over-achieved.”

“To be honest, when I played in the Top 14 I just didn’t pay any attention to the ProD2. Now, being involved in it for the past three years, it’s just a fantastic league. Not everybody can play Top 14, which is more designed towards the superstars these days. But there’s a lot of really good rugby players, who possibly just lack a wee bit of something, and it’s still a fiercely competitive league.”

Tomorrow’s Irish rendezvous in the Parc des Sports Aguilera will be their first of 30 matches, after which only the first placed side wins automatic promotion, with those ranked second to fifth entering semi-final play-offs from which one more team is promoted.

The ProD2 is given added intrigue by last season’s demotion of Biarritz after a decorated 18-year stay in the Top 14 and Perpignan, after a 103-year stay in the top flight. With five and seven championships between them, and as recently as 2008 and ‘09 respectively, this takes to 40 the number of boucliers de brennus which have been won by clubs in this season’s ProD2. But the emergence of nouveau riche clubs from bigger cities or with benefactors whose wallets match their egos, the French rugby map is changing, with Biarritz arguably the most spectacular victims.

When O’Sullivan was appointed head coach in May his fan club hailed it as a probable springboard for an immediate return to the Top 14, but it does him more credit to applaud his bravery at taking on such a difficult, if intriguing, challenge.

Even though Biarritz have the joint largest budget (€11.07m) in ProD2 alongside Perpignan, Paddy Powers’ odds of 9/4 against them finishing top, behind Perpignan at 13/8, actually look poor value, with Pau (4/1) and Agen (9/2) equally well placed to mount another push for promotion with budgets of €9.56m and €8.4m.

For starters, Perpignan only went down on points difference on the last day, whereas Biarritz were relegated with four rounds to spare and finished a whopping 21 points further adrift after winning just five out of 26 games. Furthermore, the Biarritz budget has been slashed from €16.8 million last year, amid rumours of a further donation from their 80-year-old benefactor Serge Kampf and a €400,000 grant from the Mayor of Biarritz to stave off being further demoted to Federale 1.

The ensuing exodus has seen Imanol Harinordoquy decamp to Toulouse ala Damien Traille (to Pau), Dimitri Yachvili (retirement), Raphael Lakafia (Stade Francais), Francisco Kodela (Bordeaux), Fabien Barcella (Toulon), and a host of others, with Samoan lock Pelu Taele and South African winger Joe Pietersen released half-way through their contracts.

Yet Davidson has been impressed by O’Sullivan’s initial imprint in their three pre-season friendlies. “He’s definitely improved them so far. Their contact skills are quite good for a French team. For the first time in Biarritz’s history, they say he’s brought in this funny machine they’ve been rucking with, and I know that he’s worked very hard on their defence because they’re coming up a lot harder from lineouts in particular, and you can see wee traits which could be called Irish or Anglo-Saxon.”

O'Sullivan's assistants are the former Biarritz hooker Benoit August and one-time winger Pierre Chadebech, who was asked if there was now a noticeably Irish style of coaching: "It's a system born of his own thinking. I haven't seen many teams play like that. What pleased us is the main idea; facing better and better organised defences out wide, how to find space, play in the spaces and not be satisfied to hit a wall. Eddie's thinking and suggestions will find solutions to this particular problem."

Davidson also says Biarritz recruited shrewdly, notably the 29-year-old, twice capped All Blacks lock Bryn Evans from London Irish, as a primary ball-winner, the once-capped 33-year-old French hooker Benjamin Noirot from Toulon, "and some really solid props around the place, and some other really good players for this level."

Much hinges on the Kiwi outhalf Daniel Waenga, who made little impact last season, and the veteran Benoit Baby. Nick de Luca is possibly the most notable of comparatively low-key rivals, and he is one of ten players ruled out of tomorrow's opener, including captain Erik Lund, who has been sidelined until December.

Also lurking in the long grass will be a host of local south-west rivals, Mont-de-Marsan, Tarbes, Dax and Pau, who long since grew weary of Blanco and Biarritz ruling the roost in the region. Although Biarritz Olympique would probably not exist without Blanco, in recent years his meddling has seen five head coaches in seven seasons, although he has publicly accepted he must desist from giving team talks, and O’Sullivan looks like being granted more autonomy than his predecessors.

Yet whereas Biarritz have a new squad under a new coaching ticket playing in a new league, Agen, with Philippe Sella at the helm and Denis Fogarty in his second season, have lost only three and gained six players from the squad that finished second last season and lost the play-off final to La Rochelle.

Similarly Pau, backed by the local-based petroleum giant Total, have responded to successive play-off final defeats and last season's semi-final loss, by appointing Simon Mannix as head coach and bringing in James Coughlan into a back-row which already includes ex-Toulouse stalwart Jean Bouilhou as captain.

Davidson picks Pau ahead of Perpignan, Agen and Biarritz as the leading contenders in an open promotion race. “Biarritz are definitely a well organised team with really good quality players. Each and every individual in their backline is capable of being a match-winner in this league, which is something smaller sides like us can’t compete with really. On our day, if we fight tooth and nail, and block them out, and do really well at the set-piece, possibly we can cause an upset. But realistically, we’re putting out a JCB against a Ferrari.”