When determining what deliverables are required for a project the first step is to determine what the outcome is.
If the outcome is shared understanding, then what is the deliverable that will best capture the understanding?
If the outcome is signoff of what a new solution will be, then what is the best deliverable to capture this?
If the outcome is something to guide a conversation, then what is the best deliverable to facilitate the conversation
Understand the outcome first and then choose the deliverable.