All sport can be reduced, in the end, to the battle between two opposing ideas: attack and defence, the unstoppable force against the immovable object. If you are like Shaun Edwards, the London Wasps and Wales coach, you might believe that every try comes from a defensive lapse, but at London Irish they have a different guiding principle that will not change with the elevation of Brian Smith to attack coach with England.

“I was sad to see him go as a friend and a colleague,” Toby Booth, the new London Irish head coach, said. “But we believe in the same philosophy and London Irish will be continuing in the same attacking vein. Catty’s [Mike Catt] title is attack and he was working with Brian in that capacity.

“It’s a question of emphasis more than change. Brian, I and Catty all share the same philosophy — that attack will beat defence. If you look at what Wasps have achieved statistically, they wouldn’t necessarily agree with that, but you’ve got to believe in your philosophy, because if you start chasing the ace, you lose balance.”

So, old wine in new bottles. Booth, 39, has been Irish’s forwards coach for the past three seasons and has earned respect at the club as a grafter and lineout guru. He learnt his rugby at Folkestone as a back row and then hooker and finished at Blackheath while director of sport at St Mary’s College, Twickenham. He joined Irish in 2002 as assistant academy director and has helped to put in place a proper academy, which has gone a long way to ending the idea of Irish as cuckoos in the nest. Shane Geraghty, David Paice and Topsy Ojo have all progressed from the academy to England honours.

With Catt, 36, as the player-coach, a natural ball-player stepping into Smith’s shoes, the balance is there and the transition may be as seamless as Irish want us to believe.

“It was a double act and I don’t see it being any different with myself and Catty,” Booth said, before conceding: “It has been a difficult summer. It wasn’t ideal that I was away [coaching the Saxons forwards to victory in the Churchill Cup in June] while this was going on. I was offered this job on July 17 and my priority after coming back was to quash the ‘oh my God Brian Smith has gone’ phenomenon that was probably more external than internal. I think we’ve done that.

“But Brian and I and his and my wife are good friends. I will always look up to him on a professional level, he gave me the opportunity. I hope sometime in the future I get to work with him again.” That could mean a whole range of things.

Catt, who may start at fly half, with Geraghty still working his way back from injury, is in his fifth season at the club after joining from Bath. He sees some differences in coaching styles, but said Booth has earned his respect and is not worried by the idea that he has not played at the highest level, something on which some players and pundits will inevitably dwell.

“The thing with Boothy is that he has always been with the lineouts and has been absolutely brilliant,” Catt said. “The nice thing about Boothy too is that he’s given other people things to do, whereas Smithy really wanted to do it all himself and he worked so hard, he was unbelievable work-wise, the amount of detail he would go into and that is why he will be so good for England.

“Barrie-Jon Mather does the defence, I do the attack, Boothy helps me out with that and he does the forwards and I do the backs. Neal Hatley [the former Irish prop] is now involved with the forwards.”

The different pressure of the No 1 job may become evident to Booth in an archetypal baptism of fire in Irish’s first five games of the season: Wasps (home), Leicester (away), Bath (home), Harlequins (away) and Sale Sharks (home).

London Irish had a mixed season with the high of reaching the Heineken Cup semi-final, where they lost 21-15 to Toulouse at Twickenham, counter-balanced by a disappointing Guinness Premiership campaign in which they finished seventh. They did not have enough depth in the squad to compete on two fronts and still do not. They will feel less pressure this season because they did not earn themselves another crack at the Heineken Cup.