Heroes 3 AI quirks and tricks

[Alure155]

As some of you may know, I am currently playing through Heroes of Might and Magic 3 on the Impossible difficulty. At a few points in the game, abusing the AI proved a valuable asset. During my playthrough, I have observed some quirks in the AI. Among them are:
-Capturing mines seems to cause the AI to be more aggressive than capturing towns. When I captured a town, the AI was pretty reluctant to try to take it back, eventhough I'm playing on Impossible. Whenever I captured a mine, I could expect the enemy main hero to come rushing towards me immediately.
-Defeated AI heroes come back to try to kill me again. Eventhough I have defeated a certain enemy hero, that hero will later end up coming back with another army to be a pain in the ass. This happens even if I actually destroy the hero's army without him being able to retreat. Hell, I've fought the same hero 5 times during one mission. This is especially annoying if the AI hero happens to have 300 spell points and Implosion.
-Capturing an AI town and leaving my main hero there resulted in the AI coming to recapture it immediately and killing my hero in the process. Capturing the town and then putting my hero into a sanctuary just outside the town resulted in nothing happening.
-How the AI decides whether to attack a town or not in general seems weird.

What are some quirks that you have observed in the H3 AI? They don't have to be abuseable, any oddity of the AI-whether in combat, adventure map, or town building- or the game is fine.

[Pol]

* AI have preference to secure resources, it doesn't care so much about towns, possibly because of cheating. However, if neutral mine is guarded it sometimes takes its time to fight. Also the towns have different values but is probably lower than it should be. (The reason for that seems to be some missing logic behind.)
* Hmmm. This sounds to me like a Tavern problem. If AI have just 2-3 heroes allowed in scenario, no wonder that they are returning. They cannot hire any other.
* Sanctuary near the town is known to tie AI forces, as the AI needs to clear of any possible threats, before leaving. There are two solution. Either you take town and put your hero into the sanctuary or AI put hero into the Sanctuary and will lie in wait.
* Water Walking, Fly, DD, Town Portal are all troublesome for AI. And AI cannot always properly use them. These are not only. Also AI can Fly with Water Walking and can block itself with DD on special places.
* Some of these "Spell Things" were solved in HotA.