Few things I’d answer here - first, yes Mary’s use of the bench leave a lot to be desired, both in terms of tactics in game and long term strategy blooding younger players.
However - Luc was being given time on field early in the year, but his defence and fitness weren’t up to scratch. Went back to reserves, and has improved both significantly. He was back on the bench befor Paul got injured, been in team since round 16, minutes were 28, 80, 17, 80, played 24 mins vs roosters.
Mann had a regular role resting Jack for the first part of the year, probably averaged 20/25 minutes then. IMO It probably would’ve been better for him to be on the wing and have Lawrie or Sele in that role, but it was effective.
Whether being played for 7 minutes demoralised players is pure speculation. None of us know either way.
Seibold has had a utility getting limited minutes on his bench most of the year too. Storm not that dissimilar with how they’ve used Stimson. Major diffference is the average mins for other teams is probably 4-7 minutes more, and they’ve been used in general more intelligently. But you can find quite a few games for both those teams where 1 player got 0 mins, and plenty under 10 mins.
It’s not a fact the only way they get a run is injury. If you go through how other teams do it, it’s very often dictated by injury and suspensions too. Mary is too conservative bringing them through I agree, and he needed to trust the younger players more and earlier.