I would also make sure that leadership makes it clear that they will be recognized for writing blog posts and that it is not seen as something outside their job. I know at my last role there was a Slack channel for writers and the process was integrated in Asana so that they knew where their content was in the process to publication (they cared a lot about this and would check in frequently!).
I have seen 'how we did it' posts do really well where they just write up the backstory behind shipping a product or solving an engineering problem. It's not directly product marketing but add a CTA, talk a bit about the feature/launch and it works! Some people will have high concept ideas and others won't be sure what to do. Make sure both feel like they can contribute their content -- the ideas that come directly from engineers usually do best. Also, get them to turn their conference talks into blog posts. Or take a video of them and do that yourself with the transcript.
I also think distribution is key. You need to get it on Hacker News and get your team to upvote it. There are also a bunch of dev newsletters that you can submit content to as well. You can target content to specific niches like PHP users for example as there are a lot of them, they have a developed newsletter system, and they're mostly at enterprise companies with money. And getting them to share it on their socials when it comes out!