All depends on what your line rate is.
If you want to make one machine a day, you've got inifinte possibilities on how to set up your work flow.
If you want to make one machine a minute, you've got to be highly compartmentalized and have *everything* be standardized work. No possible way to build quality in the high-volume environment without all tasks/tools/procedures/parts being highly specialized.
Being a former automotive plant quality engineer (helped build SUVs for 7 years), I noticed a lot of improvements from the automotive world I could apply to a pinball assembly line. Items such as;
Quality gates - building quality in-station and eliminating issues before they're passed down-stream.
Andon - Emprowering the assemblers to notify of quality issues and even stop the line if needed.
Tooling fixtures and jigs - helps reduce build variations.
Mutilation protection - Now that pinballs are collector/art pieces, taking care to avoid scratches/dents/etc....
I could go on-and-on....