[ Can’t be both ]

Engineers can’t be both a subject-matter-expert (SME), AND a people/leadership expert. 

This rule will of course have exceptions, which will prove the rule; because the exceptions are, simply, exceptional.

It depends if you develop in-demand, project-based, one-of-a-kind expertise (piping design, overhead wire specifications, bolt connection requirements) pursued deeply and with purpose, and therefore in demand when that skill is required (and meanwhile also being good at a lot of other things). 

Or, you focus on and prefer team-based interactions leading to leadership roles (while also being really good technically).

Know which you prefer being: technical expert, or an expert leader/coordinator.