Right now I'm using dwm and for the most part loving it. It does almost everything I want, which is great, but there is one more thing I'd like that I'm not sure what WM can or can't do, or if there's a patch for dwm to make it possible. I'll regularly watch a video while chatting, and I usually have a terminal open next to it. See screenshot for an example. What I'd like is to be able to make the video wider, which would make the terminal narrower.

For anyone who can't see the image, a quick ascii depiction of what I have vs what I want:
+-----------------+
| |
| MASTER |
+--------+--------+
| | |
| STACK1 | STACK2 |
| | |
+--------+--------+
+-----------------+
| |
| MASTER |
+-----------+-----+
| | |
| STACK1 | STK2|
| | |
+-----------+-----+
EDIT: Herbstluftwm is very configurable, and I've got exactly what I want now. :D