Tactically Proficient principles is just the same as leader ship principles, So before you can lead, you must be able to do the job. The first principle is to know your job. As a Marine, you must demonstrate your ability to accomplish the mission, and to do this you must be capable of answering questions and demonstrating competence in your MOS. Respect is the reward of the Marine who shows competence. Tactical and technical competence can be learned from books and from on the job training.