[trustmeimdrunk]

Correction: not different skills: some of these are domains and subdomains; others are approaches; others are approaches and (sub)domains. They are all mixed up in your answer, which I found to be very insightful, by the way.

Although I am admitedly far from an expert in the field in question I am not a layperson either. I say the types of activities you mentioned are of the same group of skills, in different domains, which often requires a different but similar set of approaches (based on both convention and the subtleties of the domain).

For instance making wrist watches, grandfather clocks, steam punk sex dolls, and the ankagathera(sp) machine are different use cases and require different types of mental projections and organizational methodologies in execution (approaches), but the skillsets have an undeniable amount of overlap. They overlap more with each other than they exclude. In SQL terms the size of the output of the inner join is much greater than the same for the outer join. Therefore you can say that they are of the same skill set, just like doing abdomial flexibility helps with running and bicycling hill climbs helps your breast stroke. Different muscle groups, but share many types of synergy: all part of physical fitness.

Source: 10 years as a learning specialist in business setting and aspiring triathelete.