Posts from Tactical techniques for conducting battles in Heroes of Might and Magic II. Auto-translated

Well, of course :) But I didn't say that Necropolis is a bad faction (although I personally don't like playing as it – the tactics don't suit me); I just pointed out that you need to be careful with skeletons. Maybe it would make sense to speed up the zombies first? They are perfect for dealing with enemy units.

Zombies are good, but there are fewer of them than skeletons, and they don't replenish on their own. It's better to use mummies for this – they have a curse.
I remember one battle where I used a bone dragon and 18 archers to defeat 3,000 peasants. After that, I had about a thousand skeletons, and I completed the map without any problems.

Could it be a level from the campaign featuring Lord Corlaghon?
Mummies might have a curse, but zombies are less of a loss. Besides, I usually don't have many of them – simply because I don't have enough money.

Guessed the campaign! I just accumulate skeletons, zombies, and mummies in the castle for a while: they are good for defense and will grow in numbers for a rainy day. In battle, I take skeletons, vampires, liches, and dragons. Dragons deliver the first strike (it's a pity, but they have the highest damage). Then, vampires attack the archers, and liches attack the center. Finally, skeletons deliver the decisive blow.

I don't use Liches very often. In my opinion, the problem is that, despite their high cost, they have too few hit points and therefore quickly die from direct damage spells.

Yes, for example, with a lightning strike. In this respect, they are similar to the nomads.

I feel even more sorry for the wizards in the Academy than for the liches – they are usually supposed to be the main attacking force. But then the titans come to the rescue, starting to absorb lightning strikes with their 300 HP, while no one protects the liches...
The liches also have the problem that they damage everyone – including their own undead.
But, on the other hand, this can be used to your advantage. They deal decent damage, and they are the only ranged unit in the Necropolis; if you consider that you can't expect the same as in Heroes of Might and Magic III in Heroes of Might and Magic II, then it turns out that without liches, the battle will almost certainly result in losses (but, of course, anything can happen); at least you'll almost certainly have to use magic.

Liches deal normal damage, but their main advantage (besides their unique area-of-effect attack) is their high defense stats. However, even that doesn't save them when they are constantly attacked...

Liches deal decent damage, but their main advantage (besides their unique area-of-effect attack) is their high defense stats. However, even that doesn't save them when they are constantly attacked...

It's a pity that the Lich's attack also affects their own undead creatures (if they are standing nearby); otherwise, they would be unstoppable...

Liches deal normal damage, but their main advantage (besides their specific area-of-effect attack) is their high defense stats. However, even that doesn't save them when they are constantly attacked...

Especially if they are attacked with spells...
And since they are mainly attacked with spells, it turns out that the mage option (attack over defense) is better. But mages don't attack in an area...

Liches have a defense against spells – antimagic. Cast a spell on them, and they're done for.
Necromancers are good in every way, except for their speed, which is reduced due to zombies and skeletons. But in battle, it is precisely these units that can turn the tide (teleporting hundreds of skeletons behind the walls is brutal).

Yes, I know they are strong, but I never really enjoyed playing as them... actually, I only play as them in Heroes of Might and Magic IV and V because of their insane strength.
Their tactic, due to the small number of ranged units, is "charge forward and ignore the losses"; I understand that this is justified for them (resurrecting undead after battle + the "Raise Dead" spell or something similar, I don't remember the exact name).

The Barbarians can employ a similar tactic. Their units are very strong in terms of defense and have high attack stats. Send the Wolves to be slaughtered, and while that's happening, use Ogres supported by Trolls and Orcs to deliver the main blow. And Cyclops for dessert.

Let me clarify a few things.
The defense stats of monsters from the Barbarian Castle are not the most impressive.
For example, wolves have a defense of only 2, ogres and their older brothers have 5, and trolls in both versions also have 5. Yes, the cyclops has a higher defense – 9.

Now let's compare.
Level 3. Pikemen – defense 9, golems – 10, the rest – around 6.
Level 4. Swordsmen – 9, the rest – 6-8.

In terms of defense, Barbarian troops are among the most vulnerable.

That's true, especially considering that the hero mainly focuses on attack (although not to the same extreme degree as in Heroes of Might and Magic III).
They are particularly vulnerable to Knights, but not as vulnerable to Mages – their level 4 and 5 units have more health than the others, and combat spells inflict much less damage on them. Destruction magic is especially effective against Knights, who have the lowest health stats.