Heart of Chaos

Does Irbeth really need to grow her army at such a crazy rate? And as soon as I kill her, she immediately runs away as fast as she can (this takes about a week, although after the first battle, Irbeth only returned after a month), ignoring all my cities along the way. Day 4, Week 1, Month 2: 160 Furies, 135 Minotaurs, 200 and 1 Assassins, 32 Dark Knights, 19 Devils, 32 Hydras, 24 Pit Fiends. I killed this army around Day 3, Week 2, Month 2. Day 2, Week 3, Month 2: 240 Furies, 192 Minotaurs, 288 Assassins, 48 Dark Knights, 24 Devils, 48 Hydras, 36 Pit Fiends. And here, I gave up on her and went straight to Ur-Kurgahn, defeating Grol beforehand with an army of 2 Devils and about 100 creatures of the first three tiers, 35 Succubi, and a small number of Knights and Pit Fiends. And I didn't expect Dominion to defeat me in one turn with his horde. I really liked the scenario. And I would also like to know approximately how long it takes to complete.