[Al Skierkiewicz]

j,
I would not recommend you group PWMs in such a fashion. The common wiring will make each input susceptible to noise currents present on other devices. You end up with causing unrelated failures in other devices. Individual PWM cables bring all this noise and interference back to a common, low impedance point on the DSC. However, you could position the controllers in the robot and not on the arm eliminating the need to run PWM signals to the arm. It doesn't matter where in the path the controller is located.