I think people saying Bennet "didn't get the job done" are a little precious. The best he can do is prepare a side to be consistently up there in contention. You could argue he didn't get us there this year (6th, beaten 2nd week of the finals) but he has laid the foundation of a team that by anyone's definition has a bright future ahead of it.
The club has made up its mind on him and we've got to accept the reality, but we also have to realise there are no guarantees with seibold. If the Broncos don't win it next year and siebold does it in 2020, people will say it was the coach, forgetting (a bit like griffin before bennet) that teams are built over years not a year and its the biggest challenge to keep a side in contention season after season . If bellamy gets them there after smith retires, he will have proven himself the better of bennet, but it is still an open question and he is the only coach comparable.
Siebold's success should not be judged on 2020's success or failure but the following seasons, because we broncos supporters expect the team to be up there year after year. I hope he or whoever else gets it, both understands that and does whats necessary to make it happen.
I think we over-estimate the abilities of any coach to drive success. Yes they are pivotal to it, but there is a lot more: from junior development, scouting and recruitment to the clubs finances that they rely on others for, and thats not even going into actions of players themselves.
When success or failure is determined in the last minute of a grand final, the measure is broken, because those moments are the players alone.
If Siebold gets us a top 4 spot and builds the team to compete for the trophy consistently he will have succeeded in my view, regardless of if we lift the thing.