Don't forget the Hounds of Cuculhain. Fun unit though and had roots in history.

IF you want to play BI:Total Realism, try Invasio Barbarorum:Flagellum Dei. Simply the most well done and historical mod for BI era. Sure, there's not a lot of contenders, but so what? It's go hepthalites, Lakhmid arabs and a christian Armenia, I'm content. It's also dang hard, since Roman factions have standing full stack legionary armies at the start and even though legionary recruitment is severely hindered the starting armies will give factions such as Mauri, Persarmenians and Ostrogoths some real headaches. I mean, facing a full stack of foederati, auxilia parthii(roman horse archers), clibinarii and comitatenses armatus with Persian leves and some defence-oriented elites was pretty dang hard.