My first bash at MTW :)

[DisruptorX]

The AI enjoys pumping out hordes of Varangian guards, Trabizond archers and Pronoiai Allagions.
Kataphractoi you get to see are mostly heirs.

That said, the Byzantines usually bite the dust in my games, although lately they're the ones becoming the superpower on the other side of the map.

You are right about the Varangian guards, definately. Those things can beat any infantry unit you throw at them, except maybe Huscarles or something. I suppose I just had the luck of constantly facing large amounts of heirs in one battle, then. A good 30-40% of Byzantine armies I've faced have been Kataphractoi. The first time I played MTW I made the mistake of taking on the Byzantines in the Early Period. Needless to say, it isn't worth it, unless you are the Turks or Egyptians. They are beatable, but eventually one just gets infuriated at having to constantly face armies made up entirely of heavy cavalry and heavy infantry. I never take them on directly, but let the other computers do it for me.

Speaking of which, the Eygyptians are a great faction for beginners, they have great Early Period units, a great starting position, great trade provinces, and start off right next to the extremely weak Almohads. Easy pickings.