When Railag returned to the first cities, the enemy, with large forces, tried to retake the city near the utopia, which was defended by Letos. After the last battle, Letos's army was reduced to only one hydra and a few minotaurs. He gained several level-ups.
I had to throw the plan based on disinformation into the trash and urgently develop a new one. Irbet delivered reinforcements to Letos from the second southern city. But it was already too late – he didn't need it, as the new plan was being implemented. Railag and Shadia simultaneously invaded the northern territories. Railag headed towards the city near the garrison, and Shadia towards another. The enemy no longer cared about the southern cities.
After capturing the city, Railag blocked the garrison. To do this, it was enough to position himself within a day's march from the city in the direction of the garrison. Shadia, having scared away the enemy who had peeked out of the city, went to the city near the garrison to take over from Railag. After she arrived, Railag went to capture the last city (not counting the capital), from which Shadia had departed. At the same time, he caught the enemy who had fled from Shadia and had emerged from the city again after she left. Now Railag is enjoying a well-deserved rest (he has reached his development limit) and is looking through binoculars at the enemy capital, while Shadia is leveling up on neutral creatures and looking for various stat-boosting locations, which Railag will then visit.
I took the second city at the end of the second week. During this time, Railag, with the help of Shadia and Irvana (who was purchased in the tavern, replacing Waishan in the first playthrough), captured all the mines around the first city. More precisely, he broke through the defenses, while they collected resources. Therefore, there was enough time to more or less build up the city and recruit a decent garrison. Railag set out on the campaign to the second city with even a dragon in his army (in the first playthrough, dragons appeared much later).
It is important to capture every other city at the end of the week so that you have time to recruit reinforcements in it before the next demon arrives.
If I play through it a third time, I will return to the first playthrough strategy. Everything worked out surprisingly easily there. Shadia mainly dealt only with mine-robbing bandits, who fled from her at full speed. Therefore, she did not receive a single level-up. No one tried to retake the northern cities. Perhaps I was just very lucky then – maybe the mission started in winter, and the heat-loving southerners were afraid to go north. Their clothing is clearly not suitable for the cold.
To make the playthrough easier, it is very important to level up the heroes well. And not just to their development limit, but also to visit as many stat-boosting locations as possible. For example, in the first mission, Railag, regardless of the losses, captured the arena defended by archmages. In the second mission, both heroes reached level 18 and visited all the stat-boosting locations. As a result, my Shadia is not a pushover. She has all the high-level spells of chaos and darkness. And in this mission, both of my heroes will collect everything that is on this map, both on the surface and underground. Unfortunately, my Railag has not yet been able to obtain Arcane Wave, which Shadia obtained in the previous mission.
In the utopia, you can obtain the "Portal to City" spell.