As stated above each student battles one another in a tournament system that uses units from a roster. Units cost different based on a variety of stats including morale armor and unit type, as well as any special weapons they might carry. I.e. Bows and ranged weapons add 20 points to the overall costs
My army for this class is the ostrogoths, and I am fairly certain they had slingers based on other Germanic tribes including the visigoths. I've read several scholarly articles as well as 2 books. Unfortunately it doesn't seem like the early goths cared much for their scholars. :(
Could you go into more detail on this wargame you are doing? While I sadly cannot answer the question, I'd like to know more about your setup.