Leadership is the part of your job that involves purpose and change. Management involves priorities and groups. Supervision involves tasks and individuals. Leadership principles have not changed much since Caesar was writing about his Gallic Campaigns. The leader's most potent tools are example and influence.
Strategy deals with decisions and planning that affect the entire organization.
Tactics deals with decisions and planning that affect areas limited by function, geography and time. Operational planning deals with the day to day work of achieving strategic and tactical goals. Strategy should be a process of setting a general direction while remaining flexible. Leaders need a vision of where their organization should be going. You don't develop that in groups.