How should I develop my units to defeat a Knight?

The conditions are terrible! With this, any Necromancer will be at a disadvantage...

Be more specific and justify your statement, smart guy? What's terrible:
The map? (which is one of the most balanced and popular, including on the anniversary edition)
The late game? (we were initially talking about the late game)
Maybe the fact that the Necromancer is in the Dungeon? That's not a problem, I'm ready to play underground!
The hero? (we were talking about Axel)
or
The Necromancer having a second castle?
The computers being turned off?

Let me enlighten you: in the late game against Haven (specifically Axel), the Necromancer is always at a disadvantage! My win rate: 70% to 30% in favor of Haven! The Necromancer has a chance, but it's minimal!
If you doubt it, I'm ready to prove it!