It sounds like your nephew has a project in mind. Start there with the basic dependencies and that will start laying out a competency roadmap which looks a lot like a curriculum.

Quick aside: Automate small/mid business manufacturing? Admirable, but will probably choke on the scale problem, so I think the journey will be vastly more interesting than the destination...which is good! Turns out there's a lot of robotics that can be broadly applied.

* Manufacturing --> robotic manipulation, controls, actuation, sensing, decision-making

** Robotic manipulation --> Linear algebra, likely Python and/or C++, some simulation tools

** Controls --> Manipulator platform, drivers, physical- and protocol-level choices

** Actuation --> You want to pick something up right? Air powered? Electric? Probably not hydraulic, but worth mentioning?

** Sensing --> What's your sensor suite? RGBD? LIDAR? Forces-torques? Combination of the above?

** Decision making --> FSM? Behaviour trees? Purely functional?

Repeat the decomposition and you'll probably be able to get down to the basic level of the robotics hierarchy of needs.