With the new Pi Zero board and its price, it may actually make sense to use in in place of the Arduino on Tote. It's only a little bit more expensive, after all. The problem is, it doesn't have hardware PWM and has a whole operating system that needs to boot, has to be properly configured and requires all the right software. The cost of the SD card also cannot be ignored. All the adapters and cables are not a problem, as it wouldn't need them while connected to the robot.
I started some initial testing on the Servo Blaster daemon for controlling the servos:
I also designed and ordered a PCB that makes the Pi Zero fit a little better than on this photo. We will see how that works.