In his book, Greenleaf (1977) employed a previous definition of leadership, upon which to build his treatise on servant leadership. Paraphrased, he said that leadership included going before and showing the way. In this raw definition, nothing suggests anything about rank, or status... only position (before or in front) and activity (trailblazing). Somewhere along the way, some people in Western culture (probably including Greenleaf) decided, then suggested and implied that the position associated with "going before" necessarily refers to rank and status. Although people who have served in coordinating and strategic roles (higher rank and status) might have gone before and shown the way, they have only appropriately done so when people needed them to take on that role; because, arguably, some challenges and opportunities have required the use of other forms of directing (or other factors, altogether), rather than leadership, to achieve best outcomes. Additionally, if this proves true, then not everything that executives have done or will do can count as "leadership." Similarly, neither have circumstances limited the use of the term leadership to those at the supervisory or executive levels. In any case, acceptance of these premises can result in the conclusion that no blurred lines of authority, responsibility, and accountability need exist; as long as people don't only use the term leader interchangeably with terms like manager, supervisor, or executive. For example, the junior members of military "fire teams" might lead their columns on paths, through uncharted territories. In these cases, they: (a) literally go before and show others the way; (b) have no need for hierarchical authority; (d) can fully understand the limitations of their authority, responsibility, and accountability; and (d) serve all of the others, as they place themselves in the primary target positions. Some people might argue that this does not represent "real" leadership. However, I posit that it represents a "stripped down" example of leadership, only. Furthermore, if people similarly stripped leadership of all the constructs that do not actually apply, they could then improve their overall leadership by focusing on the constructs that do apply.
Greenleaf, R. K. (1977). Servant leadership: A journey into the nature of legitimate power and greatness. New York: Pualist Press.