McFadden understands it may take some time for the 21-year-old to come to grips with his new responsibilities on the left edge, but much of the organising will be left to Johnson in his return to the No7 jersey.
Having two gifted runners in the halves might suggest the Warriors are open to exploring a more attacking style but McFadden says his side needs to be prepared to get into the grind against a Bulldogs team boasting a formidable forward rotation.
As a counter to the Bulldogs' relentless forward power, McFadden is hopeful that Lolohea and Johnson's running ability could pose problems for Canterbury's big men late in each half.
"Shaun gets us around the field the majority of the time anyway so that's going to allow Tui just to run free and take opportunities," McFadden said. "You've always got to be able to arm-wrestle because the good teams that's what they do.
"They're very similar players. What it does give us is running threats on both sides and a lot of teams have been marking heavily on Shaun, so having Tui over there hopefully will limit that.
"Those guys, even in the arm-wrestle, their strengths are their running game, and that can come to the fore when that fatigue comes in."
After experimenting with Johnson in the No6 role over the first six rounds, McFadden is confident reverting back to halfback will be a seamless transition for the 26-year-old.
"It's just a signal for him that he's the chief playmaker and he needs to make sure that he's in control of what we do. He's been doing that for a while now so it's just a number on his back really."