I played on normal difficulty, and everything went as described. My army consisted of 100 Pikemen, 30 Witches, 10 Liches, and that's it. Their army had 80 Succubi, up to 28 Summoners, etc., a lot of everything. My advice is to start the entire campaign from the beginning, mission by mission. Also, you might run out of mana. My hero has 630 mana, and the hired Magic Master has 350.
I summon 22 Dark Elementals; that's a powerful force. And I have 18 of them for each of my two heroes. You just need to eliminate them in 4 turns. Also, constantly control the gates. As long as you're defending, you're invincible. Although I have almost a complete magic set, and my Lightning Strike deals 1400 damage, even a purchased hero, maxed out in magic (and I buy him at level 19), shows very good results.
I'll try playing as Kaspar, focusing solely on magic, and if that doesn't work, I don't know what else to do. But in any case, I'll report on the progress, regardless of the outcome. ;)
