You can have one or several feeds in one posting campaign.
Mostly, it depends on the quality of the feeds. If they are updated rather frequently and you wish to post as much content from your feed as possible, you are recommended to create a separate campaign for each feed.
If your feeds are updated not frequently and you wish to make sure your blog is updated gradually, you are recommended to use several feeds in one campaign.
In either case, it is not guaranteed that absolutely all updates from your feeds will be posted. Social media posters can make only one post at a time. Blog posters, depending on the posting layout and posting frequency can post up to 5 latest articles at a time.
We also recommend using the Posting order = From newest to oldest option in the Content advanced settings. It will allow posting as much content from your feeds as possible. Your posting campaign will check your feed(s) for recent updates, and if there is no new content in the feed it will take older, but not yet published, content for posting. If there is no new or unpublished content in the feed, your posting campaign will stand by and wait for the new content to appear to post it with another run.
Read more about setting your posting campaign the best way.
You can start with one or a few feeds and then add more feeds to your posting campaign if needed. Use the Add content option in your posting campaign editor.
You can use up to 10 content feeds in one posting campaign. If you have more than 10 feeds for your campaign, you have to create another campaign to use the rest of your feeds.