Those are not steps that can be fully automated with a single Shortcut. Many things that require launching an app to be completed cannot be fully chained together.
Drafts has a shortcut action to dictate a new draft, but that is an end point. You would have to manually trigger your Outlook action after completing the dictation.
Outlook, I do not believe support any direct integration with Shortcuts or callbacks for URLs, so it is also a dead end. It can be launched with the Drafts action, but you can’t be automatically returned anywhere or continue a shortcut after saving the draft, unfortunately.
It’s not easy to sort out what actions have which capabilities in Shortcuts, so this stuff can get a bit confusing.
Thank you for the reply, glad it wasn’t my misunderstanding!!
I have a follow up question though:
Can I create a Shortcut which opens a list of recent Drafts from which I can select one, Shortcuts then opens the selected Draft and starts dictation so I can append it?
Easily. Make an action with the script as an action step. The script handles everything, so you can just have a simple shortcut to run the named action in Drafts. You can run it on any text, because it doesn’t matter what text it triggers on, as you select the draft to append to while running the script. I just left the text field blank in Shortcuts.