It sounds like a situation where you’d still want to have separate installs for each of the domains. There might be a way to do this using actual ‘multisite’ features, but personally I’d be keeping them separate as the types and purposes are different.
But you could then use RSS feeds and blocks to be able to list blog pages from the various sites on your main blog domain.
You can create RSS feeds in each site by searching for ‘RSS Feeds’ in each dashboard, and creating a new feed there.
The bit that isn’t clear is where the feed actually gets output. You just go https://yourdomain.com/rss/feed_handle, where feed_handle is what you’ve put in that field when setting up the feed.
Then on the blog site, you add ‘RSS Displayer’ blocks, referencing those RSS feed URLs you create.
You’d need to place multiple blocks on the page, so you’d still have 4 different lists, but the one page could act as a summary of all the posts, linking out to them. (if you wanted one ordered list, you’d probably need to build your own RSS block)