I did so completely randomly. Specifically, I divided it into three teams, one with each girl, and then rolled dice to see who would be in each team. (I.E: Team one, rolled a D10 as there were 9 male characters, added the number that came up to that team, did the same for team two with a D8, ect ect.) The only thing I changed was I switched the placement of Silus and Nico, as otherwise each of their teams were rather difficult to do names for, since they had two of the same letters.