Yeah, I've tried to figure the community out, and it's impossible. A lot of times, an article that I've posted gains traction, and hits #1, so I'll find other articles that expand on the idea, or follow up the idea, and they'll get buried. Strange.
I think that you're correct in that it's about who's online at the right time.
I think the timing of an article is becoming a lot more important these days. Before we got a bump in users from Arc's release, I'd post 4 or 5 articles at 3-5am Pacific time (6-9 am Eastern), and at least one would hit the front page. These days it seems there are so many people submitting new articles at that time, that the new posts get buried.
Anyway, I tend to pick users that I enjoy reading, and I read their comments as well as their submissions. It seems like a way to increase signal/noise ratio.