I'm pretty sure both the plant and the DC have both "menial" jobs and highly-skilled jobs.

You don't just chuck ore into a furnace and wait for a few seconds in reality.

No doubt there is exquisite engineering and process control expertise required to operate an aluminum plant. However, I imagine there is extensive need for people to "man the bellows", move this X tons from here to there, etc that require only minimal training and a clean drug test. An army of labor vs a handful of nerds to swap failed hard drives.