It is common for web editors and administrators not to know the standards and guidelines for building UCSF websites. Very few people have website building as their primary job responsibility.
UC Policy on electronic accessibility.
UCSF Identity guidelines
Can I use other Themes?
Can I use any of the Themes I see on the UCSF Shared root?
No, some of the themes are there for troubleshooting. For example, the Garland theme is a basic part of the Drupal installation. It's sometimes used to troubleshoot problems with the other themes. That’s why it's still available even though it doesn't meet UCSF identity guidelines...