HotA map: The Devil in Detail.

The scenario isn't as difficult as it seems. I won playing as Tower and Rampart. Main principles: 1) Acquire the "Gate to the City" in the center and master Earth Magic. 2) Free a hero from prison, either one, depending on your faction. One specializes in Snipers, the other in Wizards (the map has many of their dwellings, which is a hint). They are only needed to upgrade to these powerful units. Then, capture neighboring towns for Elves/Archers/Mages/Monks. 3) Level up your main hero as quickly as possible, without missing any buildings. The map has many libraries, which is a hint. 4) The map has the most Conflux Towns, which also hints that the main force will eventually consist of units from this faction. Additional tips: 1) Keep an eye out for interesting artifacts in the artifact shop. In particular, look for items to create sets like the Statue of the Legion/Vial of Life/Golden Goose... 2) In the Dungeon, there are 2 dwellings for level 7 creatures for each player. 3) Rampart should be captured as early as possible for the Dwarven Treasury. Without it, you won't have enough money. The financial issue ultimately defeats the main villains of the scenario. When you capture their towns at the end, there are hundreds of unbought dragons and devils there. 4) It's also a good idea to check the taverns for additional heroes (leveled up to 20 or higher). It will be faster with them. 5) Don't neglect creature dwellings, at least in the early stages.