Actually, my victories have not been due to relying on charge bonus... In fact I never chain charge (I think it's lame and exploitish). I've found that flanking fire is SO effective, that I can easily rout or annihilate twice my number in infantry troops without needing to do much melee.

What melee I do do with them is always flanking and rear work. Because of their mobility it's dead simple to do.

The only frontal charging I do with them is against foot archers (Which the AI always foolishly stick out in front of the other troops.