CHIVALRY: Medieval Warfare is a first-person medieval online combat game that seeks to deliver the intensity of epic hollywood medieval block busters to the hands of a gamer. CHIVALRY hurls the player into a fictional medieval world where the Agathian Knights are battling against the newly formed Mason Order for control of the lands of Agatha.
so what is the vanguard equivalent to? (from original AoC)
The vanguard (pictured here) is the medium infantry, most similar to the Crusader class in Age of Chivalry... though there are many changes to the class system in the new game that make this less true than I can address in detail at the moment.