I just today played with the dryad units in the sundering mod, I think they are infantry based and you have some similar ones? on the charge I saw one dryad slash 3 elven spearmen in one swing and they fell to the ground, it could be because there was more than one attack, but it looked like it was only that one dryad who had gotten a hit in, in that area, it was not 3 spearmen next to each other on the same line, it was inward into the formation.
maybe the dryad has an ability to attack really fast with both "hands" or it's based on cav.