Which Castle do you prefer to play as?

Aaaah! You're definitely not the sharpest tool in the shed! I brought this up as an example because I asked, "Where do so many monsters (dragons) come from?" and was told that they might be guarding something important. And even on a random map generator, a Guardian Shield or the Book of Earth will rarely be guarded by a harmless monster that's willing to give up the artifact for free and even join your army! Listen, let's stop talking about this nonsense! We've forgotten about it. Okay?

Diplomacy is a tricky thing to understand, even the physics engine doesn't fully explain it.
1. There have been cases where monsters that I manually set to "Bloodthirsty" in the editor joined my army for gold when I had a high Diplomacy skill. Or even for free.
2. There's a fan-made campaign called "King of the Elves" somewhere on this forum. It's not very good on its own, but in the last mission, near the castle, all the tiles are covered with 20 monsters of level 7, all of which seem to be Bloodthirsty. And you come out with a single Green Dragon and the hero's starting creature, but with high Diplomacy. You activate Vision, and you see: these will attack, and these will too... Bam! 20 Ghost Dragons join your army for free! To an already existing army!
I don't know, really. But in random maps, all monsters are "hostile" by default, and the probability of joining is -20% (according to the physics engine). They don't join very willingly.