Thomas Tuchel was monogamous, it's true. But still he was a very experienced coach. I would say Chelsea management should have given Tuchel enough time and given him a chance. But the Chelsea management has not given Tuchel enough opportunities this season. Was Chelsea's squad strong enough this season? I don't think so. The weakness in the Chelsea team is not only tactical. Their squad also lacks talented players. And because of this Graham Potter has not been able to stabilize this team yet. Graham Potter may be able to stabilize the team, but Chelsea management will definitely need to spend money and build a squad with more talented players.
To say that the manager who won the UCL for you, and overachieved in any category should have some understanding of what the formation and tactics should be. If Chelsea management believed that Tuchel was too strict, then they should have been happy that he is, because it worked, they won the UCL, I think that alone should be good enough reason to wait at least a whole year before firing a manager.
If they saw him for like 5-6 games or something and it didn't look great and fired him, then it was already decided. I know that they probably had Potter in mind beforehand and that means they were looking for any reason to fire Tuchel no matter what happened and fired him right away after few and results.