It seems if you change the list style (e.g. Roman numbered, or square bullets) in Google Docs for a list at a certain level, other sub-lists at the same level are also changed. For example, you can't have:
as changing the first sub-list to numbered also changes the second, and changing the second sub-list to bulleted also changes the first. What are the possible ways of having sub-lists with different styles, changing both list type and marker?