No silverware has been claimed yet but Leinster's stunning season has been a vindication for their coaching ticket of Leo Cullen and Stuart Lancaster.

Cullen stayed the course and maintained his cool during a difficult first season when Leinster flopped in the inaugural Champions Cup.

Lancaster, obviously, has an even bigger comeback story, falling into his current role after his England team, lovingly nurtured over four years of promise and frustration, shockingly imploded at their home World Cup.

Like Eddie O'Sullivan in early 2007, had Lancaster been forced out of his job by unforeseen circumstances in the middle of 2015, he'd probably be remembered as a decent, if somewhat unlucky, national team coach.

As it was, he left derided as a failure of Graham Taylor proportions and there was a bemused reaction following his addition to the Leinster coaching set-up in September 2016. Some fans weren't enamoured of the prospect of embracing an England cast-off. Now, he's the man again.

During the 2015-16 season, with the powerful English clubs resurgent following the re-structuring of the competition, there were fears that the Irish provinces' years of plenty were at an end.

Stuart Lancaster in his first Leinster press conference in September 2016

Two years on, it's clear that was a false alarm - what Philip Browne could justifiably call 'a blip'.

This season, under Cullen and Lancaster, Leinster have played the kind of rugby which rivals anything witnessed during the Joe Schmidt era.

If the bookies are right, they may yet achieve what Schmidt never did at Leinster and win the European Cup and the domestic league in the one season.

Schmidt's teams lost two Pro12 finals in a row and only won that title the year they absented themselves from the latter stages of the Heineken Cup.

The pair's success has been acclaimed but there has been some puzzlement about where to direct the bulk of the credit from a coaching standpoint.

Cullen wears the title of 'head coach' but the more experienced Lancaster has been given the unusual and all-encompassing sounding title of 'senior coach'.

The English papers seem to be in no doubt about who's really in charge.

In the UK press, Leinster have effectively been re-named 'Stuart Lancaster's Leinster' during this European Cup run. ('Who's Leo Cullen?' one could imagine a red-top sports editor asking on Saturday evening should Leinster get the job done.)

The Irish, of course, can't get on their high horse about this sort of parochialism. For a couple of years there, we kept hearing reports of how Bernard Jackman's Grenoble had upset Johnny Sexton's Racing Metro and such like.

Either way, Lancaster's reputation in his homeland has been redeemed to such an extent that barely a week passes now when he's not linked with one or other Premiership club. This week, he disavowed any interest in coaching Harlequins next season.

With Eddie Jones suddenly floundering in the England job, his predecessor has somehow become the man of the hour again.

There's certainly something very satisfying about the narrative of Lancaster's unexpected redemption on Irish soil.

While Cullen had a bumpy first season as head coach, he didn't suffer the ignominy and abuse that came Lancaster's way after England's pool stage exit in 2015.

As a result, many profilers and feature writers have been eager to elevate him, rightly or wrongly, to the status of quasi-head coach - or even de-facto head coach in the case of the British press.

Lancaster isn't what you'd call a Jose Mourinho style ego-monster so he hasn't, to his credit, been touring the rugby world pushing this narrative.

But is the role of the even more self-effacing Cullen being played down somewhat? After all, Lancaster's name has been touted as a possible successor to Joe Schmidt but no one seems to be doing likewise with Leinster's official head coach.

Mike McCarthy played a full season under the pair last season before retiring last summer with an elbow injury.

He says the pair have blended together perfectly. The Leinster brains trust functions very much as an ensemble. The coaches who work to the head coach are not minions simply carrying out the vision of the autocrat at the head of the pyramid.

Interestingly, he gleaned from current Wasps and ex-Leinster man Jimmy Gopperth that Lancaster performs a rather different role with Leinster than he did with England.

"Unfortunately for me I had only had him (Lancaster) for one season which was last season and I was injured a lot during it. I met Jimmy Gopperth there the other week for a coffee, and I was asking him what the lads in Wasps thought of him.

"And they spoke highly of him, but when he was with England they said he didn't really do much of the coaching. Whereas with Leinster, he does loads of the coaching. He does pretty much the attack and the defence.

"Leo's great as well, but more so with the forwards. Stuart, for instance, doesn't really get involved with the maul or the lineout.

"Leo's phenomenal with the maul defence, obviously the lineout attack and breakdown and all that stuff. He'd run the kick-off plans. And he'd have his own input as well with the attack and the defence. And he would tend to speak to the players about selection."

Prop Mike Ross also played a season under the Cullen-Lancaster axis before departing the stage last summer at the age of 37.

As Ross recalls it, the partnership essentially worked alongside the old McGeechan-Telfer lines, with Lancaster (aka, McGeechan) running the backs and Cullen (Telfer) drilling the forwards.

"As far as I could tell, Leo ran the forwards, and Stuart the backs. Leo would have had the final say in selection, and picked the team with Stuart's input. Stuart also did a lot of work on defence and unstructured attack.

"Both made a big effort to drive the team culture forward. And Stuart is big on leadership and wants everyone to lead in their own way."

According to McCarthy, neither defers to the other in the dressing room on match-day. Both are at 50-50 in terms of speaking time before games.

When it comes to Lancaster, McCarthy sketches a portrait of someone serious about self-improvement who places a premium on developing a good culture.

"He's massive on culture and creating a good environment and people being good people. He's always wanting to better himself. On various occasions, he's been away with the Atlanta Falcons and going to different environments to see different cultures and to try and be as good as he can be. He just brings so much to the table... I can't say anything bad about him.

"He wants us to train very similarly to the way Joe (Schmidt) trains the lads in terms of being - what's the term? - 'being comfortable being uncomfortable'.

"'Embracing the chaos' is another phrase Stuart likes to use. It's all about training at a faster pace and being more fatigued than you are during a game."

McCarthy joined Leinster from Connacht in the summer of 2013 and thus got to see Leo Cullen at work in a few different guises, as a player, a forwards coach and a head coach.

"Any coach that's come from a player straight into coaching has to learn on the job. But Leo did a lot of the coaching in my first year there (2013-14) around the lineout and the maul.

"He commands that respect on the back of what he's achieved as a player, being the most successful club captain. He's a phenomenal coach and his experience and knowledge of the game is incredible."

Perhaps the truth is that Leinster's arrangement isn't novel at all in rugby terms. The notion of a coaching ticket consisting of two powerful coaches at its summit goes back a long ways, back even to the amateur days.

It was always hard to tell which of McGeechan or Telfer was officially designated as Scotland head coach at any one time.

Brian Ashton - admittedly a man detested by many of the Irish players who played under him - was lauded as the visionary genius behind the great Bath team of the early 90s. And yet for most of that time, he was only the backs coach, serving under head coach Jack Rowell.

Leinster's opponents in Bilbao this weekend have a similar two-headed coaching outfit.

Racing 92 have actually gone the whole hog and not designated any 'head coach' at all. The two Laurents, Labit and Travers, have co-equal status as coaches of the side.

With Labit an ex-out-half for Castres, and Travers a former hooker who won the second ever Heineken Cup with Brive in 1997, one would imagine each takes the lead among 'their own kind' on the rugby field.

It turns out that even Joe Schmidt, who is often portrayed as a singular genius that micro-manages and personally directs everything that goes on around him, runs a similar operation, according to McCarthy.

"Joe takes on board everyone's input. I mean he's put together a backroom team that he believes in so he gets their feedback and their views and their ideas. So, it's pretty similar to Leinster to be honest."

Follow Leinster versus Racing 92 in the Champions Cup final via our live blog on RTÉ.ie and the News Now App from 4pm, or listen to live coverage on RTÉ Radio 1 as Saturday Sport comes from Bilbao.