Detroit can trade Larkin for pretty much nothing, the change will not be massive if Detroit replaces the PP contributions.
He scored 9 goals and 25 points. That's basically "plug in anyone" production. PP, in many ways, is coaching. Can Larkin's PP production be easily replaced? We'll find out.
The issue is, if Debrincat is traded and Kane doesn't return. You can't plug in Finnie and hope all is well.