A restricted layout region includes a diffusion level layout that includes a number of diffusion region layout shapes to be formed within a portion of a substrate of a semiconductor device. The diffusion region layout shapes define at least one p-type diffusion region and at least one n-type diffusion region. A gate electrode level layout is defined above the portion of the substrate to include linear-shaped layout features placed to extend in only a first parallel direction. Adjacent linear-shaped layout features that share a common line of extent in the first parallel direction are separated from each other by an end-to-end spacing that is substantially equal across the gate electrode level layout and that is minimized to an extent allowed by a semiconductor device manufacturing capability. A number of PMOS transistor devices is equal to a number of NMOS transistor devices in the restricted layout region.