Actually 2 units of Eastern + 2 units of Hillmen knocked a chariot unit to third of its strength in my last battle. They worked as a speed bumb keeping the chariot off my Horse Archers long enough for them to chew up the approaching spearmen.

Eastern Infantry are old style paper-rock-scissors. They are like the STW Ashi-spearmen. Good against cav, bad against anything else.

They have a role and they do it well.