I agree that you shouldn't focus too much on Necromancers; in certain cases, they can be very difficult to play, but there's no need to go overboard and confuse people.

Why are you so fixated on Necromancers? The Warlock will come at the end of the first month and hit with an explosion dealing 4000+ damage...

Even if you use an enhanced explosion (and you have enough mana?), with +50% earth resistance, you need 40+ spells to deal that much damage. You're quite the optimist. I've never managed to do that, not even in a month.

And a couple of hundred Obsidian Gargoyles under Celestial Shield is something else... I spent half an hour with my entire Necromancer army killing 700 gargoyles with a shield and evasion under Armageddon...

You can also put Celestial Shield on skeletons, and it will be more effective than on mages. Evasion is a real way to counter it, but you still need to get it. And you can remove it, either with a hero or with a Herald.

And against the entire army, mass slow will solve all the problems. If you can't use mass slow, cast single-target slow on the skeletons individually; they will move twice as slowly, and Necromancers rarely have Dispel or Haste...

And in response, you can also use mass slow, as well as Confusion, Berserk, etc. And with what hero will you get Dark and Light magic so that you have decent Dispel and Haste? A Knight won't have enough mana or spells. Perhaps a Mage. But to develop two magic schools in a massive way takes a lot of time, plus they are constantly given Summoning, Enchantment, and Education, which greatly complicates the development. And most importantly, in this case, there is a very high risk of ending up with no combat skills at all. And that's very unpleasant.