I also played this map. Yes, it's for those who enjoy long journeys. There were a couple of challenges with difficult enemy heroes in the first half of the game, and then I selectively recruited Archdruids, Archmages, then once Vampire Lords, and a second time Vampire Lords. With them, things went very quickly. When I reached the Academy on the north of the second continent, there was a Portal. The Wizard's Eye had already shown me where Sandro was. After jumping around in that direction, I stumbled upon a group of about 200 Vampire Lords. After gathering some strength, I was able to recruit them, and Sandro fell because 300 vampires are unstoppable, even against 100 dragon skeletons. Therefore, I didn't have to explore the third continent... And that exploration would have just been a walk in the park. I won in 137 days, and the rating was Crusader.