Gameplay tactics on the large map.

Yeah, the AI in this case always calculates very accurately and doesn't just let you run away; instead, it positions itself so that it can always reach you.
It's really difficult to break through on the third day with 60 Warriors. The hero isn't leveled up yet, and he takes them down two at a time, but he only has enough mana for two spells. So, for the Tribes of the East, this is a real bottleneck.

By the way, yes, it's very rare to be able to run away so that you won't be caught, but the computer is cunning and always knows how to position itself. And I, meanwhile, had already played a game and barely won; no attacking skills from Chaos and no Lucky Charm Wizard dropped until the end of the game (when only the enemy hero and 1 skeleton remained), and no enhanced versions of spells dropped either. In general, without an army and spells, I was on the verge of losing against Vaishana.