You can edit division templates by going to: The composition of your division can make or break a battle. Division templates can be created and modified by the player using spending army experience. The composition of each division is specified by its division template. A division is 1 basic unit depicted on the map during gameplay. The division template system is one of the key mechanics of Hearts of Iron IV.
Follow our Hearts of iron 4 best division guide step by step. In this guide you can find the best hoi4 division templates.