Having set up your site and added content to it, you can now use the Cloud Sync
feature to collaborate with your external partners.
You'll sync your content to the cloud. Your marketing consultants will be able to edit it without having access to your on-premise network, whilst you maintain visibility of their edits. Once the updates are complete you will unsync the updated content from the cloud.
You'll then also create a task that must be completed by a cloud user.