About AI – the intelligence of the computer.

I completely agree. In Heroes, the five mage heroes are quite weak. Although... the AI skillfully uses mind control, celestial shield, and berserk, and nothing is scarier than that. I'll try changing the spell priorities. By the way, you can set priorities for artifacts, but I don't know about spells...
By the way, the AI is VERY smart in magic, tactics, and character development in Heroes 3. That's where you find a worthy opponent! That's why I often play Hota.