The Pikeman are effective against non-ranged cavalry (also ranged if the enemy doesn't use hit-and-run) and buildings, and the Chu Ko Nu's are highly effective against Heavy Infantry and Light Cavalry. The Chu Ko Nu has a greater multiplier against Heavy Infantry and Light Cavalry than most archer units, especially with Repelling Volley, increasing the multipier from 2x to 3x, making it highly effective when micro-managed properly.