They(Armenians) where certainly unique enough. The Hayasdan would have the mounted power of the Sarmatians and Skythians, but with all the perks of a settled nation too. Hayasdan would have Light Cavalry Archers, Armoured Cavalry Archers, Cataphracts, Spearmen, Armoured Spearmen and competent bowmen. The thing is though, why would they include a relatively minor nation like Armenia when they can include heavy hitters like Skythia, Odrysia(or Dacia), Germania, Ptolemaioi, or the Seleucids?