I played with the same technique I used on my panorama time lapse with some still images. It is an interesting way to display stills on video. It requires one video for background and then slide show videos for as many tiles as you want. I did 3 slide shows. I rendered this video at 1280x720. Here are the steps:
1. I created 4 video tracks on my video editor.
2. I put the background video on the first track and set the opacity to 60%.
3. I put each of the video slide shows on a separate video track.
4. I changed the size of the slide show videos to a width of about 500
5. I moved the x and y axis of each slide show video to space them equally.
It's really a pretty easy process and creates an interesting presentation. Just thought I'd share what I have been playing with....
Greg
https://vimeo.com/214329732/6766a93d7a