I decided to check if the Orcs could handle the Necromancers, and I did. I crushed that Necromancer like a hot knife through butter (please, Necromancers, don't be offended:)), and that's despite him having 3 cities plus an Elven city. Of course, I had problems too, especially with gold; I had to exchange resources for gold.

I don't know, I don't know... It depends on who you're playing against.
In general, Orcs aren't very good against Necromancers. I was playing as the Undead, I had 2 cities (1 Elven), and my opponent, who is better than me, chose the Orcs. He also had 2 cities (both Orcish), and I easily defeated him! Although he had learned the "Silence" spell, it didn't help him. I used the "Mind Control" spell (Puppet Master, Puppet, I don't know what the correct translation is, my translation is bad :) ) and "Summon Phoenix"! Although he had a larger army. So, it all depends on how each player plays :)