Posts from "Weak demons"??

There's no need to enable quick battles. You should do it yourself.

And there's no need to enable quick combat. You need to do it yourself.

It is well known that ranged units, in this case, the Adepts, will target ranged units (in the Demons faction, the Succubus and its upgrades). If there are no ranged units, they will target Imps and their upgrades. Therefore, before the battle, if you are not sure that everything will go without losses, remove the Imps from the field. You don't need to remove the Succubi; they are already strong, and they also retaliate.

People are writing nonsense here; it's actually very effective for demons to clear out neutral creatures. Perhaps it might be a bit challenging at the very beginning, but the losses are small. You split up the Imps and open portals with all of them. They either take the hit or deal return damage, after which the main forces finish them off. For all other races, I have more losses from clearing out neutral creatures, except perhaps for Necromancers, but even then, it's due to various reinforcements after the battle.

The Dark Elves have the easiest start when it comes to clearing neutral creatures. But for Demons, any archers or dryads at the beginning equal significant losses. Deleb is not considered here.

The Tower faction is only better at the very beginning, when you have Assassins and Furies. There is usually enough mana for one battle, if you don't constantly run back to the Castle or to the fountain. But a little later, when you have most of the units, Inferno is better, because the gates take the brunt of the attack, while the Tower usually loses at least someone in a normal battle, especially the Furies don't live long.
Archers are not a big problem compared to other factions. You divide all the mobs into 7 groups and open the gates, then cast the Curse on the archers. They will only have time to shoot once, then the gates will block them and they won't shoot anymore. But they often manage to shoot once even against other factions. So there are no more losses here either. It's more difficult with spellcasters, but Dryads hardly deal any damage. And dogs and horses reach the large archers on the first try, as well as the small ones, if you increase the speed by one with some boots of speed or use a tactic.

I still disagree about the Inferno. You can advance against even large armies without losses. At the very beginning, Furies take out all the infantry, Stalkers take out all the archers, including mages (although the hero will need mana for this).
Demons are among the worst when it comes to fighting neutral ranged units. Before the gates open, all the archers will have time to fire once, and the Inferno creatures are, to put it mildly, not very durable (tactics and boots may not even drop later). But mages are different - you put out only Gargoyles and calmly defeat the enemies with arrows/fireballs. Or Gnomes. Improved Guards hold up well.

Furies don't always eliminate everyone at once, but they are often the primary target for enemies. Even single spellcasters and archers won't reach them unscathed on the first try without tactics and boots of speed. And assassins won't be able to eliminate everyone.
Demons are unlikely to be significantly worse. They might fire once, but who won't they manage to fire at?
For example, compare Elves and Demons in a battle against archers, especially when both sides have other units in their army, particularly if there are 2 or 3 groups of these archers. The archers will fire once at the Demons, but then the Demons will block the path and do their job along with the Cursed Sign.
The Elves will definitely take at least one hit before they reach the archers, and then the Blade Masters will retaliate, if they don't finish them off immediately. The Fairies might strike without taking damage, but if they don't finish the job, they'll get hit again, just like the Blade Masters. But the archers won't attack the Demons again. As a result, the Elves are unlikely to suffer fewer losses, and may even suffer more.
If we consider the High Elves, the Furies also won't reach the archers immediately and will take a few hits, because the assassins will only poison one group, and while they're dealing with everyone, the Furies will get hit again. You can try using only Hunters, but that's only if they hide in stealth first and if the hero has enough mana, which is questionable at the beginning.
With third-tier units, it's easier for the Elves, but it doesn't help the High Elves much. The Demons' dogs can reach the enemy quickly, but only with additional speed, otherwise it's the same as before.
The Undead also suffer a lot of losses, but you can resurrect them, although you won't have enough mana for everyone at the beginning.
For humans, the archers on the second level help, but there will still be losses.
The same situation applies to the Orcs.
The Dwarves can reduce losses by keeping their first-tier units, but they will take too long to deal with the enemy, and if they deploy Javelin Throwers, they will suffer losses. The Dwarves suffer heavy losses at the beginning, and only later do they become overpowered.
Magic is the only thing that saves the Mages; they have enough mana at the beginning, so they can minimize losses.
So, it's not clear why the Demons would suffer more losses. But this only applies to archers. And if we consider melee units, it's even easier for them, especially against larger melee units.