You don't get any choice about being a leader. If you're responsible for a group, you have a leadership role and you will be treated as such. Your only choice is whether to be an effective leader or not. Everyone responsible for a group does Leadership work, Management work and Supervision work. 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.