Currently, I'm playing on the same map. Level 200%. I arrived at the same result as Bes – the need to access the blue tent, but through a different method. The main army consisted of Humans, with whom the main heroes of the purple and red factions were destroyed. Meanwhile, Dessa leveled up on secondary heroes, after which, gathering the aforementioned "cap" mentioned by Bes, he reached the blue tent, providing the Humans with access to the center. Next, 4k Elementals, and the destruction of the purple faction. I haven't figured out what to do next; I can't spend a week on the game. The main thing in the game is to act quickly and aggressively.
At the very beginning, it is necessary to: