If u got 3.5 m lance, with some skill you can screw 2 or 3 men in one charge....

rather off the topic question:
What about halberd armed cavalry? they should like Guan Yu (3 kingdoms), and they will hack their way in extremely brutal manner, plus, they had excellent chance to survive in melee... (they are elite cavalrymen in ancient china afterall, why not the saka or sauromatae encountered them and copy them?)