Necropolis or Castle (Which one is stronger?)

I would say they are equally strong. What can really stand against a horde of Archangels from a castle? Not vampires, not ghost dragons, and not even zombies. You might be surprised, but it's the most ordinary warrior skeletons. Which a necromancer can create practically out of thin air. Legions of skeletons, about 4,000 units + a well-developed hero-mage + haste + (if you're lucky) an artifact that grants +1 to unit health + a player with brains playing as the necromancer = we tear through everyone. Playing as any other faction, I never hoard level 1 units – I throw them in as cannon fodder, distracting from more valuable units. With Necropolis, I can't afford to do that – in this castle, only two things are truly valuable, its highlights: practically indestructible (with skillful use) vampires and hellish necromancy, which allows raising skeletons in large quantities. It would be a sin not to use this, especially when playing against Archangels, for example. So, for example, I tore through about 20 Archangels belonging to a developed hero, cutting them down with skeletons. But, again, I repeat, you need to know tactical techniques, be able to use magic skillfully, in particular resurrection, haste...