All organizations should have a plan; This is true even if it doesn't work out. If there is no plan, there can only be reaction to events, and that may lead the organization into an undesirable outcome. Leaders can push and pull organizations down a desired path that may or may not work; but it is more likely to happen than not. 

All top managers should be involved in the strategic planning process. This is true even though they may not be knowledgeable in all facets of the company operations - sometimes it is an education. For example, strategic planning involves marketing, financing, engineering, human resources, and technology. All of these facets and others are considered and discussed during the planning process. Human Resource managers should be able to discuss and understand the engineering and financing and so forth.