I like your concept here Dave, though for me; I find 2 concerns. One is a visual thing. I think it is difficult at best to discern the sense of space surrounding a hidden-line image as volumetric. In fact, it appears more 2D than 3D. 2ndly, I find the texture of the spheres distracting. perhaps smoother and even more transparent may read better. My suggestion might be to utilize three viewports , with the third being a draft render, also somewhat transparent, to define the tanks volumes. I'm sure others can help further. Good luck!