Think about your plumber. You would not think of having him or her 'on staff' in your house so that they are available to deal with the occasional challenge that crops up. Much better to use them as a hired gun. Bringing them in for a specific task that is beyond your core competency/experience, where there is a clearly defined objective (clarity of purpose), where specialized thinking or tools might be required, and where the mission creep can be monitored.
The same rules could well apply when you need to resolve operational leadership challenges. By operational leadership challenges we mean all aspects of running your organization (tasks, teams, talent and growth) as opposed to delivering your product or service.
Often operational leadership challenges manifest themselves in such things as an inability to grow the bottom line through winning new or organic business, all levels of leadership struggling to succeed, or internal projects that impact the entire organization being poorly planned and executed.
The issues mentioned above may not, in the first instance, require extra hires or re-organization (moving house) you may just need to call in the plumber. This hired gun will have the competency, breath of experience, capacity, objective (clarity of purpose), specialized thinking and tools, and task definition to focus on understanding the problem, developing the solution and then leaving you to focus on what you do best.
There is nothing wrong with companies using hired guns (a different way
of thinking about consultants) - as long as they use them the right