A healthy school needs to have both an open and proactive Head and an inquisitive and activist Board. The two solitudes approach of "this is my territory and that's yours" is definitely a recipe for eventual disaster. Now that is not to say that Boards should be involved in the day to day minutiae of operations, but they should be provided with any and all information that they require to effectively exercise their oversight function. I first cut my teeth working with Boards in the public system in Ontario. Long before KPIs became fashionable (or the term had even been coined), those Boards took meticulous efforts to carefully examine each financial decision made, or assess each programme introduced. They questioned staffing decisions (positions, not personnel) and were acutely aware of all aspects of risk management. They were not interested in running operations and making decisions, but they saw their jobs as ensuring that after we administrators had taken some action, spent some money, or created some new position, that we were able to explain the rationale clearly, answer any and all questions, and give detailed reference materials (external research, performance statistics, prevailing trends. etc.) to support our actions. An inability to do so would be a negative assessment of our own leadership and administrative abilities regardless of the inherent value of what had been done.
This is not a case of a Board micromanaging, but rather of it flexing its fiduciary muscles and ensuring the accountability of both the Head to the Board, and the Board to its stakeholders.
Activist Boards are more than just Strategic (although they are that!), they are demanding (within reason) and responsible. Boards that are passive, and that follow a narrowly constructed definition of their own areas of interest eventually create complacency (or even arrogance) in the attitude and approach of even the most dedicated and talented Head, creating a situation which eventually can lead to major misunderstandings and an unpleasant parting of the ways. Not surprisingly, looking back over the history of many failed independent schools, you can usually identify a dysfunctional partnership between Board and Head.
Interestingly perhaps, the Boards that are the most vulnerable to moving from activist to passive are those with excellent Heads. The Board gets used to depending on the leadership and management strength of the Head and ceases to pay close attention. If that Head falters, or moves on and is succeeded by someone less capable, the school is ripe for a major - perhaps fatal - breakdown. The fault for this lies on both sides of the equation, but ultimately, it is the whole school community that pays the price.