Auto-translated
Colleagues, I'm having internet access issues, so I can't actively participate in the discussion.
I'll just say that, as Ergon correctly pointed out, the damage from towers should be greater than the troll's health. For example, the damage from towers to trolls is around 85-95. This is, of course, with a second guild built (defense is presumably taking place in the computer's captured Castle). The further line of reasoning is approximately as follows: we calculate how many troops the AI can have, taking into account the additional increase at a level that is impossible to determine. We estimate our hero as approximately 0-0-4-3 (starting Warlock, visited two level-up locations for a thousand experience points each), and then we calculate an approximate battle. This is for the second or third week of the game (like a Barbarian with an army from the second week). Once, such a hero of mine grew to 1-1-7-6 (withstood three assaults) and then easily destroyed the main forces with the same spell (but already with troops).