Wherever you are, death will find you, even if you are in towers strong and high.
— The Qur'an, 4:78
While not exactly as powerful as its mediaeval successor, the Trebuchet, the Hawtun-p'hau ("crouching tiger siege engine") is still a veritable force to reckon with depending on what mods it emerges in. While some units are meant for use primarily against buildings, and others against infantry, the Hawtun-p'hau however can deal additional damage against both targets, thus making it ideal for general-purpose use. Its only drawback is that while it can be very effective in the "siege" role, it has a strong handicap, if used against other war machines - particularly ships and other siege weapons - as well as cavalry, the scourge of most siege weapons in all the mods this unit can appear in.
As a result, you are advised to have contingency plans should you encounter more powerful siege machines, especially the Ballista and Catapult from Age of Empires. In which case, your main concern should be the preparation of dedicated light cavalry squads to take out the offending enemy units, before too much damage is done.
WARNING - Hawtun-phau is being adjusted in Swords of the Prophets for scale,
- Machine: scale = 0.5
- Men: possbily at 0.94