Horse Archer Armies...(long text)

[Deus ret.]

If they are set up for a killing filed, I have to bring my cav up and risk them gettting attacked if they can take the siege engines down

yep, even more so since AI artillery units display a terrible proneness to hit your general. I don't know how it's done but if I deploy siege equipment, most of the times I'm happy if they manage to inflict at least some damage, whereas my general seems to magically attract enemy missiles. Probably I don't employ him correctly, but openly attacking siege equipment often remains a risky task for me.

[Peasant Phill]

It's a known that generals have a higher chance of being hit by siege engines than other units. It works on both sides. It is however considered a cheesy tactic to use in combat.

[Empirate]

AI controlled siege engines have been a pain in my behind whenever I've happened to deploy my forces in range of them. Almost every shot hits at least something, whereas my own siege equipment can be said to follow the reverse statement...
But I never lost a general to siege engine fire, not once in playing M:TW extensively for years. I managed to kill the odd AI general with a large rock from time to time, though. Just yesterday, it happened again in my Aragonese campaign, killed a five-star Italian prince defending against my two-star captain with a zero-valor Catapult.

[gaijinalways]

I usually have found siege engines to be pretty useless for hitting things, instead preferring regular troops that are easier to control.

[caravel]

The catapult towers are great at shooting their own gatehouse to pieces.

I only train an occasional catapult, until gunpowder is invented.