Necropolis and Demon.

No, you are simply overestimating the Necromancer's capabilities. Taking the Castle of Daleb isn't that difficult, considering the skillful management of machines and the ballista with fire arrows (which essentially ignores half of the armor, meaning even through a wall, the damage will be considerable). A catapult has a 40% chance of destroying a wall/gate/tower with a single shot, and if the gate is breached, the siege won't last long. And the gatehouse will provide decent assistance during the siege. As for gathering "hundreds of dragons," it would require astronomical amounts of money, especially if there are a lot of cities on the map, or if the map is standard, i.e., 1, maximum 2, neutral cities, it will take about 5 months of game time. The only undeniable advantage of the Necromancer over the Demon is a relatively easy start. It's quite difficult for the Demon to defeat some monsters that the Necromancer handles better, and if there are losses, the Necromancer quickly replenishes them with necromancy. I base my judgments solely on my experience in online battles, where I played exclusively as Necromancers for about six months, and the highest percentage of defeats were inflicted upon me by Demons. In skilled hands, the Demon is a very dangerous opponent; I don't play as Demons often myself, as it's quite difficult for me. P.S., I've been playing online for 2 years, about 130-150 games. So, I haven't played that little, and I can draw my own conclusions. Yes, and also: in "Lands of Exile" on the "Hero" difficulty, you shouldn't even try to defeat Kaspar in the first week. The Plague Tent deals damage in the first week that is comparable to a volley from a rocket launcher. Only the Academy can withstand this, thanks to the gremlin saboteurs.