Successful coaching leaves a real artifact: a decision that stops escalating. Nothing tracks it, because every system built to measure a manager's work records what happened, not what stopped.
A manager's authority is granted along the org chart. Accountability is granted along the outcome, and outcomes never respect the org chart. That gap isn't a bad-company problem.
Management gets called a fad only because most organizations install it as a practice with nothing load-bearing under it, not because management itself is fashion.
Your real span of control is the number of people who can meet a written review standard, not the number authorized to approve. Most organizations have never written the standard down.
Management Coaching of Wyoming, LLC