In our org. we have 2 roles:
1. Product Manager - Who owns the Idea and is responsible for updating idea status.
2. Category Manager - Who should be informed when the idea is updated (Basically a watcher)
The above 2 roles are similar to what the Creator and Assigned to fields can do in Ideas.
Ideas received are processed at multiple backend systems and assigned to a product manager before it is bulk uploaded and the product manager is not always the Creator here.
Category manager needs to be added as a watcher by default to all ideas that will be uploaded and Assigned to is the only field which can do this.
The field names Creator and Assigned to are hence misleading