Awakening of Evil

Maybe I'm not the best player, but on the 4th mission, playing as the Warrior, by the end of the 3rd week, I was almost finished clearing the dungeon, when suddenly, literally, an Elf flew in with an army almost 5 times larger than mine and headed straight for me. With logistics maxed out, this Elf still flew almost a quarter of the distance further than I did, which ultimately led to my demise. Maybe I'm really slow, but HOW do you build an army identical to a hundred archers, dancers, and fifty druids by the 3rd week?! And it's not just one Elf; a second one with a similar army is already approaching the entrance. I'm far from a Heroes guru, and I specifically set the difficulty to Warrior just to enjoy the campaign and the story, but even with that difficulty, something isn't quite working out. At the beginning, everything was great; I reached the garrison and the city with almost no losses, but then assassins wiped out two-thirds of the Furies. In the city, the enemy hero again used spells to destroy 70% of the remaining Furies. I would be very grateful if someone could help me with advice on how to complete the map, perhaps with an optimal build or strategy.