I won it, on my second try. I did a total freaky improvisation there. Looked around, the battle filed. And I figured that hill behind me was perfect to hold defence. So made all my units bar cavalry run up that hill as soon as possible. 1 or 2 cohorts had to fight off the cataphracts but being a sivler (or gold?) star units, they put up a good fight. Meanwhile my general (very powerful it seems) charged the cataphracts who were right at the bottom of the hill - it was a fast and easy affair - their general was dead before they knew what was coming. I was lucky 2nd time around to get most of my troops up on that hill.. Well, a few cohorots, and the shameful remnants of cavalry who had to fight their way through on the top. But while he was on the way there, my cohorts were routing the poor horse archers who had to engage because they either couldn't shoot up the hill or used up the arrows. now it was very close, I think it was luck, but I concentrated on killing off HA general unit - after he was dead, and it happened very early = his unit was sitll full = the fight turned into one routing disaster for the people in pink pijamas. I won and it was fantastic.

My guess is it was a fluke, because that doesn't look like suggested strategy, but it was fun to try and when it actually started to pay off - who knows, try it if all fails. :)