Sieges: Are some units better than others?

[Finalgenesis]

Interesting, so hawks have a specific penalty on them for purpose of sieging only? Did not know that.

The rule book and forum post I read supports that mindless unit suffers 90% penalty to it's siege defense value, but it sieges normally. Eg. Lobo guard does great sieging, but blows on defending sieges. I think it was said that this mechanic is to stop massive undead (LA Ermor) from holding unbreakable castles.

As for the animal tag, it is also gleamed off of post from more knowledgable old hands, you can get to the "lies my rule book told me" thread through the strategy listing post stickied on the forum. From what I understand, summon animal horde would be pretty handy for defending siege or doing the sieging themselves.