For me it's a error that the Numidians are excluded from the factions, are more important at this time for the roman and mediterranean history instead of the Sabeans or Sakas, especially sakas are a very useless faction, if can a modder replace this faction with numidians is very good, the Sabeans can remain but is better if replaced with a Greek (Siracusa is better) or a Illyrian tribe factions. And the Sabeans has a very limited number of unit and is natural for a faction without a strong expansionism, and lack of historic sources, Numidians hasn't this problem I think.