Fortress vs. Necropolis

Hero leveling takes a long time due to the large maps and the frequent presence of water, plus a significant amount of money is spent on heroes and troops: 1 at sea, 2 on land, and 3 on defending the castle and supplying troops to the main hero. Now, about leveling: I level up Chaos and Summoning because the hero is strong in magic, and Luck/Logistics/etc. as much as possible.
The Necromancer levels up Logistics, and thanks to the power of magic, he will even out the chances of winning with his undead forces.
As for raising troops from corpses, he uses Domination.