There's a severe mana shortage, seemingly only at the beginning, but later, with increasing levels and army size, "Reinforcements" should be sufficient in most cases, with rare exceptions. By the way, "Drain" is cheaper in mana cost than "Healing" and "Regeneration" and is often more effective.
Цикл "Закадычные враги": "Особенное гостеприимство, "Супероружие", "Меж молотом и наковальней"
"Падение Шантири"
Кампания для "Кодекса Войны"
"Выбор Сагиттеля"