3-71. Division headquarters further provide subject matter expertise to assist brigades as they prepare for missions or capstone training exercises. Low density military occupation specialties or specialized units may benefit from the division consolidation of training events. Divisions usually have subject matter experts in the low density specialties who develop, implement, execute, and evaluate training programs across several echelons. (See ATP 3-91 for a further discussion of the division roles and responsibilities during operations to shape.)