A Simple Answer
For a while now, I’ve been trying to get the K2 Rolling Archives to work properly with the way I want them to show 3 posts per page. I had gone over my code again and again, and it seemed to be the way things should be.
Then, I was reading the K2 Forums, and out of the corner of my eye read something that twigged. In the WordPress Reading Options, you can set the number of posts per page.
Now, when you use the Rolling Archives above, three posts will appear for each "page".
Sweet Candaaay. Bam. (re The Big Zapper, upholder of "Brannigans Law")