I get your argument MS but this whole board has been saying that the defence needed to be overhauled in order for this team to truly contend. Basically any outside observer has been able to identify this need, unfortunately this was lost on the previous management group.
Your argument doesn't align with what management has actually done, rather it's just arguing against a scorched earth rebuild. Basically you say that a full rebuild/tank wasn't realistic (it wasn't) and then you hand wave until it justifies your position. You keep framing a 1-2 year retool as a rebuild in service of your argument of the status quo - "go forward".
I think Colorado is an easy counter example to your argument. They clearly traded parts of the previous core that enabled them to let the group that won last year to progress.
At the time of the Duchesne trade in Nov 2017:
Mackinnon - Year 2 of 7 year deal at $6.3M (8.6% CH, 22yo)
Landeskog - Year 4 of 7 year deal at $5.6M (8.7% CH, 25yo)
Rantanen - Year 3 of 4 year ELC deal at $0.95M (1.3% CH, 21 yo)
Tyson Barrie - Year 2 of 4 year deal at $5.5M (7.53% CH, 26yo)
Matt Duchene - Year 5 of 6 year deal at $6M (9.33% CH, 27yo)
They got rid of Barrie, hit the trade home run with Toews, and pushed forward with their core group of 3 players. Before Miller and other signings:
Hughes - Year 2 of 6 year deal at $7.85M (9.63% CH, 23yo)
Pettersson - Year 2 of 3 year deal at $7.35M (9.02% CH, 23 yo)
Demko - Year 2 of 5 year deal at $5M (6.14% CH, 26yo)
Horvat - Year 6 of 6 year deal at $5.5M (7.33% CH, 27yo)
There are clear parallels with Hughes and Demko being signed to good contracts with another 3+ years remaining. EP, like Rantanen, is a year or so from possibly getting a substantial pay raise. Barrie and Duchene are older players who seemed like they were part of the core but got shipped out.
Five seasons later, they're raising the Cup.
I think that if you sat EP, Demko, and Hughes down and said that this was the plan and that they would have to let Brock walk and not extend Miller in order to fix the defensive aspect of the team that they'd understand.