If members of the MusicBrainz community could work hard to craft their edits so that they adhere to the guidelines as much as possible and to add supporting links to their edits, that would fit the bill of “being conservative in what you do”. Then, when you consider other edits, be liberal in accepting other people’s edits. If an edit makes the database better, vote yes, even if you don’t fully agree with it. If you see a small mistake and you’re an auto-editor, accept the edit and fix the small mistake. See if you can find a way to accept the edit, rather than shooting it down.
Our attitudes shouldn’t be “How can I shut this person down?”, but “How can I help this person make better edits?”. If an editor gets shut down for small mistakes, the editor is going to be discouraged from doing more edits. This harms the project overall! But, if an experienced editor politely helps a less experienced editor to improve their edits, the less experienced editor will feel more welcomed and is much more likely to continue learning and to continue making more edits.
After all, happy teams are vastly more productive than unhappy teams.