Don't all machine shop supervisors have to perform most of those duties? As much of a manufacturing engineer-maintenance-troubleshooting-setup-scheduler as actual supervisor??
Kind of the point being made, companies keep adding to the list of skill sets and responsibilities of a top tier machinist's but not the pay increase.
At this point they are machinist, computer programmers, production/manufacturing engineers, machine maintenance and repair techs, then add supervisor, or manager to that, .......
when does it stop really, or when does the pay get more towards what the other job descriptions entail, a simple engineer makes more or the same as mentioned.
I did the same thing in as a custom car audio fabricator,
wood working, upholstery, composite manufacturing, welding, vacuum forming, automotive paint, electronics integration, audio/acoustic engineering, mechanic, motorization integration....
at what point does someone actually get paid more for incorporating other job description skill sets.