New recruits Todd Lowrie, Dane Nielsen and Thomas Leuluai are noted defenders and will lift the standards but pronounced attitudinal, structural and technical issues need to be addressed.
"My beliefs about defence are pretty simple," McFadden told the Herald on Sunday.
"It's all about discipline, attitude and working together, not by themselves.
"This competition is about 26 rounds; we need to build a standard that we become known for and maintain it."
Along with head coach Matt Elliott, McFadden, 34, will bring a significantly different defensive structure to Mt Smart but says the basics don't change.
"Whatever defensive pattern you may use [sliding, umbrella, 'up and in'] will depend on a few different factors," says McFadden. "Whatever you do, the main thing is to all be on the same page. You need a team approach with no excuses.
"Defence is always the hardest part of the game - especially for young players. Most are picked for their offensive abilities and have to develop the defensive side."
Elliott knows about last year and the year before.
"The Warriors came to Penrith and we were flying," says Elliott. "We had all the ball but couldn't get through in one of the bravest defensive displays I have ever seen. Many of those men are still here."
Elliott refers to round 18 in 2010 when the Warriors held the Panthers scoreless in the second half to take a 12-6 win, despite a lopsided penalty count (11-3) and the Warriors making 59 tackles to eight in the opposition 22.
Next year, McFadden will also look after the halves and work as a general kicking coach.
It is early days but it sounds like McFadden is leaning towards playing Leuluai at halfback and Shaun Johnson in the No 6 jersey.
"Thomas is very experienced and he will need to take on a lot of responsibility for leading us around the park," says McFadden. "With Shaun, you don't want to tie him up too much. To a degree, you want to give him free rein and let him roam to use his skills."
He also added that Feleti Mateo, who has played a handful of games at five-eighth over the past two seasons, couldn't be ruled out as a halves option, given his "exceptional skills".
As a player, McFadden was a speedy halfback, forming the famed 'Mac Attack' with fellow playmaker Mark McLinden at Canberra between 1997 and 2001. Stints at Parramatta (2002) and Melbourne (2003-04) followed before a groin injury forced him into retirement at 26.
His coaching career started almost immediately, returning to the Raiders as Jersey Flegg coach in 2005 (under Elliott).
He has been at Queanbeyan since, apart from a stint as an assistant at Catalan Dragons (2007-08), his first year coinciding with Stacey Jones' last.
"I was a bit stale and needed a new challenge," says McFadden. "As soon as I heard about the Warriors opportunity, I pursued it fairly vigorously and I think it worked out best for all parties."
Asked for the major influences on his career, he lists Ricky Stuart, Ruben Wiki and Laurie Daley on the playing front and Brian Smith and Craig Bellamy in terms of coaching philosophies.
"Ricky was in the game all the time and had a kind of ruthless intensity," say McFadden. "That's what we have to build here. Brian opened my mind to the complexities of the sport and Craig - well, everybody knows what he is about.
"At the Storm, they have an aggressive, intense team approach underlined by the fact that there are no excuses; you are paid to perform and that's what you do."
Warriors' defence 2002-12
Best: 2006 (4th best in NRL), 2007 (4th), 2011 (4th).
Worst: 2012 (14th), 2004 (13th).
Average: 8th.
