Since many of the Italian allies fought with the same types of equiptment, tactics, and training as "Roman" units, in EB the Hastati, Principes, and Triarii available outside of Roma actually represent allies as well. They could have their own units with different skins, but that would take up more unit slots so EB decided to represent allies that fought the same a Romans with the same unit. If their were unlimited unit spaces I'm possitive that EB would already have variation amongst the Italian allies, but we are stuck in the engine...