This year's French champions Castres and the team that had one hand on the Heineken Cup in 2010-11 before Leinster snatched it from them, Northampton, as well as Ospreys are a bunch capable of derailing the best made plans of new man in the RDS, Matt O'Connor, in next season's Heineken Cup.
Do Leinster have a bogey Welsh team? Ospreys have turned them over when it mattered in recent years but yesterday's draw for the 2013-14 group phase of Europe's premier competition all adds up to a difficult Pool 1 for the Challenge Cup and Pro 12 winners.
Northampton owe Leinster something from that Millennium Stadium game and a second half narrative borrowed from fiction with Jonny Sexton’s intervention after Leinster went 22-6 down at half time, while Ospreys denied the Dublin side a Pro 12 title last year, 31-30 on a sunny day in the RDS.
With luck, Leinster could have drawn Zebre as their Tier 4 club but got Castres, the only question there being if the financial clout of the French team can span both competitions and whether their domestic championship form can transfer to Europe.
"The pool looks really strong because Ospreys are in a bit of transition as well, although I would expect them to perform better than last season, which was their worst performance for a long time across all competitions," said former Leinster and Ireland wing Shane Horgan.
"You saw what Ulster did to Castres in Europe earlier in the season and then all of a sudden by the end of the year they are French champions.
" It isn't a nice day to go down and play and Leinster have fallen there a couple of times. Northampton will have lost a couple of big names as well, but it looks like a difficult group to get out of and one where teams can take points off each other.
“There won’t be any blowouts. But there are teams in transition there: Saints and Ospreys are and Castres are losing their coaches as well.”
Munster, with Perpignan, Edinburgh and Gloucester in Pool 6, will concern themselves with patching up a few positions in their own squad before worrying about those visiting Thomond Park. But drawing Edinburgh as their Tier 3 club instead of Scottish counterparts Glasgow will work nicely for them.
Perpignan, back in the tournament after a few years’ absence are ranked 14 in Europe, with Gloucester ranked 23 and Edinburgh 15 to Munster’s six.
But who to replace Doug Howlett and Ronan O'Gara with will be coach Rob Penney's critical call. That Munster beat the French side twice in their pool in 2009-10 seems scarcely relevant given the changes that have happened in Thomond Park in the last three years.
“I think Munster are less in transition than they were last year,” added Horgan. “It will be interesting to see who they go for at 10. If they go for JJ Hanrahan that might be a really good starting point for them.
“It is either him or Keatley but that will be a demonstration of the type of rugby they want to play. I think Hanrahan is a serious bit of stuff. I love the way he plays, it’s exciting.
"Howlett is a loss but it's up to others to stand up. Leinster were in a similar situation with (Felipe) Contepomi. The Munster backrow had some of the greatest leaders ever and they're now developing guys who can fill their boots."
Ulster, with English bulldogs Leicester, Montpellier and Benetton in their Pool 5, started well in the season just gone but in the end won nothing.
Coach Mark Anscombe needs to have everyone fit or recruit to sustain their competitiveness on all fronts. Leicester, ranked 13 in Europe, Montpellier 20, and Benetton at 29 to Ulster's seven look good on paper.
There’s no doubting the province are now a force but they do need to tweak.
John Afoa at tighthead clearly wasn't operating at the level he can at the end of the season. The operation to fix an arm muscle will keep him out for a possible three months but it should have him fit coming into the new season and that will help.
Luke Marshall's return from concussion and the blossoming of younger players Craig Gilroy, Paddy Jackson, Iain Henderson and Stuart Olding augurs well.
Connacht, with Pat Lam facing into his first season in charge, will inevitably be viewed as one of the two weaker sides in Pool 3 alongside favourites Toulouse and England's Saracens.
It it looks like a clear scramble between France and England. As you will hear a lot next season – there are no easy games in the Heineken Cup.
Round 1: October 11th/12th/13th, 2013; Round 2: October 18th/19th/20th, 2013; Round 3: December 6th/7th/8th, 2013; Round 4: December 13th/14th/15th, 2013; Round 5: January 10th/11th/12th, 2014; Round 6: January 17th/18th/19th, 2014. Quarter-finals: April, 4th/5th/6th, 2014. Semi-finals: April 25th/26th/27th, 2014. Final: May 23rd/24th/25th, 2014 (in France, venue to be confirmed)