I once managed to be a member of the old guard AND the leader of the new guard at the same time. This put me in a position to steer the organization despite not having an official leadership position.

The old/new division was heavily driven by organizational policy. I was accepted into the old guard mostly because I arrived before policy changed, as well as personal friendships. I was the leader of the new guard mostly because I agreed with and built on the policy that defined the new guard.