well, the pre-marian units were not remarkably superior. its not until the marian reform that they gain their superiority. still not statistically. romans wons much due to their flexibility. and failure on teh other side.
the great greek empires seen in the previews were crumbled to bits before the roman army came to them. I'm not saying rome accidentaly conquered the world. but rome wasnt a superpower from teh start.
so statistically i predict that rome's elite unit (seen so far) the preatorians will be equal in stats to the torikatai argyraspidai of teh seleucids. or the Spartan Hoplitai. just guessing here, i'm NOT an EB member