Johns wants Cronulla to switch Hynes to six and Trindall to seven next season.
On Nine's 100% Footy, Johns said this formalised their roles.
Trindall organises, while Hynes runs the ball more.
"I think the first thing next year is Trindall's got to put the seven on, and Nicho's got to put the six on," Johns said.
Johns says it could relieve pressure on Hynes, the 2022 Dally M Medallist.
"He's there for another three years… this year they've been playing that way. Trindall's been the on-ball halfback," Johns said.
"I just think psychologically, just changing the number will help Hynes."
His call followed Cronulla's 46-10 finals loss to the Sydney Roosters, when Hynes suffered an early concussion.
Johns also cited the 38-18 Round 26 loss to Parramatta without Trindall.
"When you're the highest-paid player, you own the result, especially if you wear the seven on your back. With that money comes responsibility," Johns said.