Are there really no zombies here? Obviously, that's not the case.
When the military led the survivors over during the relocation, quite a few zombies followed. However, they were met with a barrage of missiles from the Rocket Armies that decimated the ground! One could say that Changhe Base was created through bombardment.
You can imagine how strong the First Legion must be with such equipment.
Of course, after discovering that some zombies could resist radiation and only grow stronger if not killed by the blasts, nukes and many missiles became unusable or were simply depleted...
Therefore, the First Legion gradually kept a low profile, but their acquisition of Crystal Cores and supplies from killing zombies continued; this was the capital for their growth.
Take the Second Legion, for example. Why are they ranked second? Because their core force is a remnant of a pre-apocalyptic Air Force Airborne Troops!
