Given that Leinster lost back-to-back Champions Cup finals in 2022 and 2023 by a grand total of just four points, there was a strong argument to be made that they were doing very little wrong.
Even when taking Toulouse to extra-time last year, their first season under defence guru Jacques Nienaber, they were just a yard wide with a dropgoal which would have won the match. Again, tight margins.
In those three games, the first two against La Rochelle in Marseille and Dublin, the better, smarter team won on the day.
So something had to be done and while the process of changing Leinster's DNA began in December of 2023 when Nienaber, a double World Cup-winning coach from South Africa arrived, yesterday looked like the job was complete.
Take the opening salvo of the 2023 final in Dublin - when a free-flowing, energetic, precise Leinster attack put 17 points on a stunned La Rochelle - and then look at how Leo Cullen's side beat the same side yesterday; it's chalk and cheese.
Every tackle, 194 in total, Caelan Doris and Josh van der Flier the main men, was a statement of intent, like dogs with bones, eager to show off to their master.
They crossed for one well-worked try, which was "too soft" according to La Rochelle boss Ronan O'Gara, but this was a game won in the trenches.
Speaking on the RTÉ Rugby podcast recently, Bernard Jackman said Nienaber's bid to breed some Springbok dog into the Leinster classes was working.
"He's turned south county Dublin players into proper psychos. There’s an edge to nearly every one of them."
However, the focus on defence means less time for attack and the truth is that as they have become more aggressive without the ball, they are less effective on the front foot.
It was something Robbie Henshaw alluded to after the defeat at Tottenham Hotspur Stadium last year.
"We were a little bit, I don’t know, not ourselves in that first period," said the centre after Leinster had uncharacteristically failed to convert good chances in the Toulouse 22.
At this stage of proceedings last season, Leinster also had three wins in Europe but a points difference of +53; they are +33 after the 16-14 victory yesterday.
They had scored 13 tries in the three games to eight this campaign.
It's a new approach and it's working, at the moment.
"I think they’re definitely harder to play against, but are they better? We’ll see in May," said O'Gara after seeing his side lose to Leinster for the third game in a row.
While La Rochelle had been struggling this season, the game at Stade Marcel Deflandre was still Leinster's best test to date.
Even if the hosts were without Will Skelton and Jonathan Danty, Leinster’s confidence that they can match the big boys will only increase.
Of course, the ultimate test will be how they deal with a La Rochelle, Toulouse or Bordeaux in a knock-out game.
The latter two are already qualified out of Pool 1 with Bordeaux, on track for maximum points if they take five at home to Sharks of South Africa, likely to take the number one seed.
Well beaten by Toulouse in the Top 14 final last season, UBB have scored 23 tries in the group stages.
Defending champions Toulouse are just two behind on 21.
Leinster’s eight, and that failure to pick up more than one bonus point means they will need to take a maximum haul against Bath (5.30pm, live on RTÉ) and hope that Toulon, away to Sale Sharks, don't do the same and make up the points difference (-10).
If that scenario played out and Leinster missed out on a top-two seeding, down the line they may find themselves in France for a semi-final, something that they haven't experienced since 2021, when they first locked horns with and scampered away from Stade Rochelais.
"Congratulations to Leinster, they’re better, but I hope we get another crack off them this season because our boys can do better and will do better," added the former Munster and Ireland out-half.
"Some teams that play them might feel that they are beaten already, for us that wouldn’t be the case.
"We analyse them and go through what the facts are and they have been scoring less points but they have been giving up less points.
"Home advantage is big too, we’ve got to be really disappointed with losing at home.
"It’s not a crushing defeat, but it’s still a big defeat."
The Leinster fans have been largely understanding of their recent shortcomings, minute as they were.
Now that Cullen, with the best resourced province, has RG Snyman and Jordie Barrett at his disposal, a failure to get the job done this year may see that patience run out.
"From a defensive point of view, we have made a very conscious effort that we want to be more aggressive," Cullen told RTÉ Sport last week.
"We want to be a strong attacking team, that’s part of the DNA of the club. We want to set the standard of the way the game is played, in a positive way."
They can't have it all, however, and the only way to tell if it was the right call will be the colour of the shirt of the captain lifting the Champions Cup in May.
Watch Leinster v Bath (kick-off 5.30pm, Saturday) on RTÉ2 and RTÉ Player or follow our live blog on RTÉ.ie/sport and the RTÉ News app or listen to live commentary on RTÉ Radio 1's Saturday Sport.
