I think document is good for filling the details, but it will not solve all the problem . And I kind of hate Architect with an extreme authority from top to the bottom and just assume people know everything. From my experience, casual communication between developers is an important factor in software development.

The perfect role of architect I believe is an individual contributor. People just come to ask your idea and respect you to make the majority of design. And you need to help other to understand your idea.