If you follow the JAMstack model there’s no need to insert that data into Ghost.
Instead, you can either pull the data directly from 3rd party services, or use your cron to compile the data somewhere else, and pull the two things together in your frontend.
There’s quite a few different ways to achieve this, i.e. publish a list of popular post slugs/ids and using the API to fetch those posts, publishing a pre-populated list with all fields, or adding a #popular tag to posts that are most popular and using this to pull related posts that are also popular.
E.g. filter=tag:[{{primary_tag.slug}}, 'hash-popular'] would return posts with either tag, but automatically ordered so that posts with both tags are first.
There’s quite a lot that can be done without having to amend Ghost core to cope with specific use cases. We’re actively working on our APIs and webhooks at the moment to facilitate this way of working.