Collaboration can be excessive, but it can also sometimes be helpful.
For example, if a draft is made available for someone else to review, then someone can comment in case they find something wrong that the original author does not (it is also possible that the original author might find something later that was not originally found).
For example, if a draft is made available for someone else to review, then someone can comment in case they find something wrong that the original author does not (it is also possible that the original author might find something later that was not originally found).