I figured out the first map of the "All or Nothing" campaign. I managed to assemble an army by recruiting monsters along the way. All I had to do was explore the map. This army was enough to clear the Cursed Forest of undead. For this, the forester agreed to build a ferry, but first, I had to reach the shore and see that there was no ferry. Thus, I crossed directly to the exit. It turns out that all the other tasks, except for the forester's, are not necessary. They only give war machines and a spellbook. Although, it is possible that I am mistaken. Perhaps the scenario is not working correctly for me.