Some Lucid Thoughts...

The Twin forces which guide a career path:
1) Skill Set
2) Domain Knowledge

Any career path is a delicate balance between the two. The 'ideal' career path is a compact yet flexible skill set targeting several interrelated domains. The two extremes are a narrow skill set with narrow domain knowledge which is often seen in engineering fields. The other end is a flexible wide (if not well developed) skill set and overall domain knowledge across various domains.

Thus the main aim of designing a career path is to find a balance between Skill set development and acquiring Domain knowledge. The depth and width of both being important factors.