As an example of the tactical master that is RTW, last night I beat a huge army of Parthian eastern infantry. It was a magnificient sight. There was about 2000 of them, all in purple line stretching far and wide, marching slowly to meet my meager mixed line of militia hoplites, levy pikemen, skirmishes and light calvary. Surely the AI would use it's massive advantage in infantry to plow straight into my lines, overwhelm my pikemen and with their spears keep my light calvary at bay.

Then my calvary hit them with javelins from the flanks, my skirmishes hit their front and the whole big purple line went everywhere. Infantry men were running at my skirmishng calvary and infantry, turn their flanks to my hoplites. I just hit them in the middle with my hoplites, some fought, most ran and my calvary ended up with tons of kills on the routing troops. They had me beat with that mass of infantry, all they had to do was suffer some minor casualties from javelins until they reached my troops. When they split up to chase the skirimishes and calvary, their mass was difused and any advantage in numbers they had was diluted. I took the day but it felt like a hollow victory.