Take the Tyre Nichols incident for example. The arresting officers failed to employ several fundamental tactics that would have resulted in a better outcome.
https://web.archive.org/web/20220128201854/https://www.washi...
If the police are doing the wrong thing, then they need to be taught how to do the right thing. Cops have a lot of extra scrutiny and protocols than moat other professions, and they obviously want to avoid ending up in jail. Good training should teach the correct way to react to situations, and then actually put them through those situations
Even something simple like "how to cuff someome who is resisting without using nonlethal weapons" would have helped a ton. This is a task that you actually need to practice rather than just read about in a book