How can you build Wyverns in the first week if you need 15 units of wood, and the lumber mill produces 2 units per day? It takes 8 days to gather 15 units. Or are the resources scattered across the map taken into account? And if there aren't any? It's not that easy to build Wyverns without wood.
Справочник по НоММ-4 http://handbookhmm.ru/pamyatka-dlya-heroes-iv.html
Памятка по НоММ-3 http://handbookhmm.ru/pamyatka-dlya-homm-iii.html
и HotA http://handbookhmm.ru/vyishla-obnovlennaya-pamyatka-dlya-homm-iii-hota.html