Trimble can dazzle in city of lights
Right winger aware of French strengths but also knows about their many frailties
You can talk until you are blue in the face about any defensive system.
The binding trust begins with that between a coach and his player.
When Les Kiss departed Ireland to become Ulster's Director of Rugby, Joe Schmidt recruited Andy Farrell in what looked like a master move.
The former England defence coach would have to tend to his roses until his 'gardening leave' expired, at least in the international arena.
This left a void at Ireland for the duration of the Six Nations and into it would first step Wales.
Schmidt must have planned and prepared for the best, but feared the worst.
In the eighth minute, Wales came calling with their freight train attack.
It was heavy collision action that had Ireland stretched to breaking point.
From the 14th phase in possession, Wales full-back Liam Williams was cut down by Keith Earls knifing into his left hip and Simon Zebo into his right shoulder in what could be best termed scramble defence.
Two rucks on, Wales trusted their big men in the wide channels. Luke Charteris got the ball away to Alun Wyn Jones with Tom James unattended on the outside.
This is when Andrew Trimble made a ball-and-all textbook smash that saved a certain try.
"Now, it's probably a slightly different system," said Trimble.
"There are a few differences between now and the World Cup, maybe in light of the World Cup.
"I mean it's important that we keep our width and get off the line with a little bit more line speed whenever it's appropriate.
"It is just making sure that everyone is on the same page, knowing that when we go forward, we go forward together, and when we go sideways, we go sideways together.
"You could pick any number of defensive systems to work with and they would all work if everyone was on the same page and that is the most important thing for us," he said.
Since then, Zebo has fallen to a sore knee and Earls to concussion, leaving Trimble and the Kearneys, Rob and Dave, to mind the house, so to speak.
France will bring a completely different challenge to Ireland's refashioned defence. Guy Noves will test out Dave Kearney with Teddy Tomas; Trimble with Virimi Vakatawa.
"No disrespect to Alan Wyn Jones but this guy (Vakatawa) is incredibly dynamic, the power in his legs, he's going to be a handful, he really is," said Trimble.
"He showed against the Italians, if there is any lack of communication or lack of togetherness, he's going to be really hard work.
"But that is only one of their wingers and Teddy Tomas is the other one and he's a big threat as well."
It suits Ireland so well to talk up Vakatawa and Tomas for what they can do with the ball.
For all of their strengths on it, there are matched by their weaknesses away from it. The Fijian played his first 15-a-side match for over two years last week.
There are so many holes in his defensive knowledge and practice.
The same goes for Tomas. He can grease the wheels of any attack and simply be absent without leave in defence.
It would be surprising, to say the least, if Jonathan Sexton did not to look to turn them and test their catching under pressure from cross-field balls.
It just makes sense. You look for a weak point and you go after it.
For all of Schmidt's complaints about the squeezed preparation and the late selection issues due to injuries to Zebo and Earls, he has been Ireland coach for over two years.
That is more than two years of bedding in his systems, tactics, strategies, ploys, schemes and players.
This has been backed up by two Six Nations championships.
There is also the benefit from knowing they can win in Paris.
"I look back on Paris 2014 with very fond memories," Trimble said.
"I look back on previous years with not so much pleasant memories.
"I think Paris has the tendency to be quite exciting.
"It's a good place to go. We have the potential to have an amazing weekend.
"But it's extremely daunting as well, just the threat that France pose and we'll have to have our wits about us.
"I think we go there with a healthy mindset in terms of the confidence on what we can produce, but just a small bit of a fear factor which I think is a healthy way to approach it."
France came fourth in 2014 with three wins from five and fourth in 2015 with two wins from five.
Their World Cup was a debacle. Their 62-13 failure to New Zealand was an embarrassment.
This is what their coach Guy Noves had to work from when he got his hands on his players just two weeks ago.
The French were disjointed and disorganised in a somewhat fortunate 23-21 defeat of Italy last week.
France v Ireland, today 2.25 (live rte2/bbc)