My personal opinion, from listening to the players and GMBM over the years, is that a huge part of Barry’s value was in leadership, loyalty, and the overall mindset of the franchise. He set examples and structure that were extremely important for the team as it came out of the last years of George and the Oates fiasco. That was more important than the actual X’s and O’s for them.
As the seasons went by, and Barry’s mindset and structural baselines became indoctrinated, the X’s and O’s piece became more and more of a focal point. So much so that it’s what “seemed” to prevent the team from winning a Cup in 17, by losing to what looked like an inferior team in Pittsburgh. The franchise then allowed others (ie: Reirden) to have more and more authority in the game management and planning, to the point it became a very shared responsibility. More than it is with other teams. Subsequently, they won the Cup.
Now, it’s probably very debatable — even to the guys in the room and to the coaches themselves — as to who was ultimately responsible for the game plans that won it all. We all have our own opinions (I don’t think it’s at all a coincidence that the team’s success seemingly coincided w Reirden’s ascension of authority), and perhaps this years results will shine added light to it all.