The intelligence-gathering never stops. They have played each other twice already this season and the entire Leinster coaching ticket travelled to Paris to take in Toulouse's quarter-final win over Racing 92 for good measure, but Leo Cullen and Co will still be trawling through footage for an edge against their French opponents ahead of Sunday's semi-final.
At least it's entertaining viewing for the analysts. Last weekend, the four-time European champions welcomed Clermont to Le Stadium and served up a rip-roaring 47-44 victory.
Sofiane Guitone's try saved Ugo Mola's side from their third defeat in 23 games and extended their lead over Clermont at the top of the Top 14 to eight points.
And it came amidst a slew of changes, with Romain Ntamack consigned to the bench.
When he was introduced, the youthful France star scored a try and helped rescue the result.
Still only 19, Ntamack has been the break-out star of the season. He's far from the finished article, but his ability to break games open has grown as he gets more time on the pitch at the top level.
With France, he's been playing at out-half but Toulouse prefer to deploy him in the midfield with Zach Holmes pulling the strings at No 10.
In January, Leinster were able to expose some of his defensive weaknesses but he already looks a more rounded player.
Felipe Contepomi was a player who shifted around the backline when needed and the Leinster assistant sees plenty of promise in the French starlet.
"I think he's a very talented guy... I've been lucky that I've played most of my career in club rugby as No 10 so when you play as 10 and have the capability to play 12, it's much easier to switch from 10 to 12 then do it the other way around," he says.
"The other way around is very difficult so if Toulouse see him as a 10 and play him week in, week out as a 10, yeah, put him as a 10 and he will be more than capable of playing at 12 in a French team.
"But it will be hard the other way around. That's my feeling.
"I can give you a lot of cases of guys who were 10s... but Juan (Martin Hernandez) in Stade played at 15 and club level played 15, sometimes 12 so when he comes to play 10 it was harder for him the last few years, he was taken all over the places.
"So as a 10 you have to playing there week in, week out. That means that he could then play in another position, because he's very talented.
"But we'll see where his (Ntamack's) best position is, there are so many years to come and he's a very talented player.
"What I can say is that French rugby, they have some very young talented players that are coming through.
"You can talk about Ntamack but (Antoine) Belleau, the Toulon No 10, also playing.
"So there are many, many good young players. (Antoine) Dupont is only 21 and Ntamack is 19, so it's great and how he has been, as a youngster, exposed to all that rugby in the last few months, it's been unbelievable.
"What's his best position? I don't know yet and I think he's such a good player that he's still looking for his best position whether it is 10 or 12."
Whichever position he plays, Leinster will have to watch him closely.