Walkthroughs for custom maps.

As I understand it, we're talking about the map Audaciousness. I'll take a look at what's going on there sometime.

Yes, it's about that map, I forgot its name, thanks.
I looked it over in the editor and just "ran through" it with cheats.
And it caught my interest. It looks like it will be the next one in my walkthrough.

Briefly about this map:
Wisdom and Earth skills are banned. So heroes who have "Wisdom" as a starting skill need to be looked at closely; they can learn Armageddon + Fire and use hit-and-run tactics if necessary.
Earth can still be obtained once from a Pandora's box at the starting respawn, but you need to open the quest obelisk before 117 to get the artifact from the guardian. The box will give Logistics + Earth + Wisdom. Though you'll have to break through a formidable guard of giants to get to it. I.e., one way or another, one hero will be able to fight.
So the main hero needs: Wisdom + Logistics + Earth from the Pandora's box. Plus obtain/buy Fire + Intelligence (I didn't notice a mana doubler).
Pathfinding can be skipped; for the 3 remaining skills, you could consider Attack (for devils - the main striking force), or Magic Resistance, or Tactics/Defense. Tactics + Air looks good on Mullich, allowing you to strike the enemy hero first.

Heroes will be available in the tavern; you can buy "unusual" characters like Mephala, Deesa, Gunnar, the hero with the Prayer spell, etc., if the AI doesn't buy them first. But since Wisdom can't be obtained, Andra with Elleshar, Mullich, or Deesa look good for the main hero role (if you can buy them at the starting respawn and deliver them to Earth magic, of course).

Development at your own respawn won't be very fast; there are no resources or gold at all, you'll have to count every penny. The main stack will be wyverns from the hives.

At the same time, the AI is free, can travel to foreign castles, strengthen itself, and relearn magic.
Further on, after entering the AI's respawn, you'll need to use fast roads to capture all castles in 1-2 days, having first stationed whatever leveled heroes you can for splitting (or buying new ones in the captured castle). Necromancy castles have the "Resurrection" spell by default (a key spell), and in Inferno you can try to get Berserk. You need to reach them before the stronger AI heroes can attack us or damage the Inferno.

In general, Fire magic can apparently be fully learned in castles. With Inferno and Efreeti, you can use hit-and-run tactics against especially dangerous heroes.
Overall, the map looks doable, though you'll have to work hard, especially at the starting respawn.

Archangels and Clone can theoretically be placed in one castle, but it won't make a difference. Also, in a Utopia, you can get the Water spell book (others are banned), as well as the Ring of the Magi for + rounds of magic.

These are my thoughts on the map, which I'm attaching.