The usual story told about the Fremont NUMMI plant is that it was a disaster (drug use and prostitution occuring on the grounds) under GM and that when it was taken over by the Toyota joint project with the same work force (and union) became highly productive.

https://en.m.wikipedia.org/wiki/NUMMI#History

In this telling it's the GM management who are incompetent, not the line workers. Clearly that's not the version you're selling though.