I've never talked with the ARL PAO folks about open source, but in general you're right. They have several writers who have to cover everything ARL does (that they can talk about). So they're like most civilian reporters: generalists who talk to experts to learn enough about an event or subject to write a report for an audience that knows less -- or nothing -- about the subject.

Full disclosure: I work in the PAO at RDECOM, of which ARL is a part.

For a given repo Github gives you the daily number of visits and unique visitors, as well as the number of times the repo was cloned (they don't give you the number of downloads of the zipped sources).