From publisher blurb:
Onward! Forward! To Battle!
In battle, chaos reigns supreme. The lamentations of siege weapons blare across the plains while the sound of hundreds — perhaps thousands — of clashing blades rings through the air. Individuals band together into troops, forming a single unit that for all intents and purposes acts as a single monster. Troops are constructed similarly to swarms, made up of many component creatures and providing more punch collectively than any single creature could on their own. Troops allow low-level creatures that would otherwise pose no challenge to an adventuring party to suddenly become dangerous opponents. The troop subtype also allows the GM to easily run epic, cinematic battles for higher level characters. Monster Menagerie: Troops presents 10 troops to deploy against your PCs, ranging from the CR 1 toy soldier brigade all the way up to the CR 19 heavenly host. Whether you employ a gritty human “band of brothers” or fantastic legions sure to inspire—or terrify— your players, Monster Menagerie: Troops has everything you need to make your players fear the art of war.