The Bregman signing was absolutely the right thing to do. We needed a big RH'd bat for years. We needed to make a major step at improving our defense, and our corner IF slots have been the very worst on D for several years running.
No doubt, we should have handled the situation better. We had our manager saying Bregman would be a great 2Bman. We had our 3Bman clinging to the idea he was a plus defender at 3B and was promised by the old regime he "was the 3Bman." While I don't blame management for thinking and expecting a player to do what is best for the team, they have to anticipate that all players may not agree with your view on what is best, and once the saw pushback, they should have handled it better. Maybe Devers was so set in his ways, that nothing would have worked, but the reports are that Cora never even asked him to play 1B. That exposes some serious dysfunction at best or insubordination by Cora and or Devers at worst.
I've aways felt Devers could become a better defender at 1B than Casas, who sucks at D. Getting Bregman should have made his move to 1B or a DH/1B share with Casas the plan. At worst, they should have told Devers we want him to be the DH, but that 1B is on the table, and he should start practicing 1B, even before Casas got hurt. This is not hindsight babbling on my part. I've been saying this for years.
Brez, Cora and the FO dropped the ball, no doubt, but that does not take Devers off the hook. It was clear he was being belligerent and was not willing to do what was best for the team. Those Oakland and Yankee players involved in feuds were the opposite, IMO. They would give anything to win and do anything to make their team better, even with their massive egos.