I think Kevyn's fault (which I initially thought was a strength) was that I got the impression he communicated two ways with Terry and got Terry's input/buy-in on all major moves. I think he tried to steer the club in his desired direction, but within the constraints Terry put on him.
I feel that Jarmo is aware of this dynamic and accepted the position only after putting boundaries in place with respect to Terry's inputs/buy-in/meddling. I hope that he told Terry that while he appreciates that Terry is an avid fan, he needs to stay out of the decision making process, barring certain, pre-specified conditions. Instead of the guardrails being on the GM, the guardrails will now be on the owner.
In exchange for this freedom, Jarmo has promised certain milestones be reached with respect to making the playoffs, winning playoff series, etc., and if he doesn't make the promised milestones then Terry can re-evaluate Jarmo's position as GM. Executive positions typically have expected targets/goals. Terry will understand if Jarmo demands certain freedoms in exchange for commitments to team goals.