Like what Ciaran said. The long pikes are actually a separate model. If you use phalanx unit, they stowed away the actual primary weapon and put the long pikes which has its own set of animations, regardless of the soldiers' animation. This also caused some glitchiness when fighting close range and your formation got scattered and your soldiers move around all over but their pikes would still point at the same direction as the group. So when engaged in anything but in phalanx formation, the pikes get stowed away and they use their secondary weapon.