And versatile McLaughlin, who has been know to sing bass in the RTE Philharmonic Choir, has sung the praises of Schmidt's regime.
"There's incredible cut-throat competition, like nothing I've experienced, in this squad," McLaughlin told the Irish Sunday Times.
"But we sat down a few weeks ago, before the Munster game, and made an agreement amongst ourselves.
"We knew a lot of big game are coming up, with very marginal calls being made and we decided then and there that every body was digging in for the squad.
"So there's an incredible morale there at the moment, an incredible buzz. I've never been in a squad as tight as this before.
"We had a really good disciplinarian for the last few years in Michael Cheika, who was a really hard, tough forward, himself and really knew his forward play.
"But I think Joe maybe takes it to a different level in terms of knowledge of every position. It shocked me how much he knows about forward play.
"On top of that, Joe really hammers home this thing of being a humble squad and everyone buying into the team ethos.
"In other years, maybe we'd a tendency not to respect teams enough. We maybe thought, 'We're Leinster and we deserve to win' and there were numerous examples of us losing games as a result, or only scraping home.
"Having humility means not being too big for any game."
McLaughlin, who can play in the second-row or back-row, anticipates a real forward battle against the Saints, an attritional war which will count upon every member of the match day squad.
"Watching the match between Northampton and Leicester earlier in the season was fascinating, given the number of turnovers and successful counter-rucks.
"Northampton aren't a whole lot different to Leicester in that they try to bully teams. "They've a big set-piece game, four or five really dangerous forwards in the pack and a dangerous counter-attack. But essentially they're a power-based team."