Vertical tabs need an extra step compared to Drupal 7

In Drupal 7, I regularly used the Vertical Tab option to organise my fields into groups consisting of a list of vertical tabs. All this required was to create a set of groups and define each as a Vertical Tab.

In Drupal 8, it appears that this now requires a three step process:

1. Create a Tabs group (set to Vertical).
2. Create one or more Tab groups (set to Vertical)
3. Nest each of the Tab groups inside the Tabs group.

This had me confused for a while. It would be useful if this could be added to the documentation. Happy to add it to the documentation page myself if this behaviour is as designed.