Agreed. Check out the cabinets we build for an idea of how controls can be mounted in a limited space, yet still look uniform. Although we've never done a panel so small with a trackball, simply dropping it in place of where player 2 would usually be should be fine, assuming the surface panel is deep/wide enough to accommodate the trackball you intend to use, and you account for the large interior space the trackball housing takes up inside the control panel section. I highly reccommend the U-Trak from Ultimarc for it's 'contained' housing, easy mounting and lack of a need for a mounting plate.