Resilience

I didn't manage to win using only Orcs. It's difficult for heroes without magic, and Orcs don't have it :(
Initially, the map was designed as a "who can last longer" scenario. Then, I set a time limit for victory. You can trick the AI: harass it with Imps until the time runs out. You can also buy a Sorcerer in the tavern and level him up. A Wall of Swords or a Crystal of Secrecy can do terrible things to the AI. Also, the mage Hafiz is imprisoned in the dungeon. The only question is, where to get them)))
I can suggest reducing the difficulty, as I mentioned before. If you like the map, I can create a simplified version.

Reducing the difficulty, I believe, won't help with the Orcs... their starting position (if you start with Hagesh) is already quite easy. Harassing with decoys is a viable strategy; in principle, I completed the entire mission based on that, but at the end, the AI stubbornly attacks the Castle. The map is good; I wish there were more like it. There's a real lack of challenging maps in Heroes. (I don't play modifications that change the game's content; I prefer the classics.) It shouldn't be simplified; I just want the map to be playable with each race, and to achieve that, I'll need to change a lot, not just simplify it. Regarding magic, if Orcs are given the ability to hire a large number of low-level creatures, "Wrath of the Horde" will be a formidable weapon. That's all they need.