A restricted layout region includes a diffusion level layout including a number of diffusion region layout shapes to be formed within a substrate portion 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 substrate portion 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 total number of the PMOS transistor devices and the NMOS transistor devices in the restricted layout region of the semiconductor device is greater than or equal to eight.