I can't draw it in the reply, it's weird.

Well anyway, the bottom enclosure has a heat panel on the right side of the cage, and the light is on the left side of the cage.

The top cage has a divider in the middle so there's two heat panels, and there are also two lights.

The cage on the right side of the divider is getting all that belly heat from bottom cage, because the heat panel is right under it.

If I put the top enclosure on the bottom, the same thing would happen but then the now bottom cage would be getting extra belly heat.