Against which factions is it easier for demons to fight, and against which is it more difficult?

Oh, I might have gotten carried away. But still, you can hire archers on the third level for the Elves, while for Inferno, you can only hire demonesses on the fourth. And you can hire seven Elven archers at once, while you can only hire five "demonesses" unless you build upgrades.

You didn't get carried away at all!

Absolutely correct! It is indeed very easy for the Wood Elves to fight against demons. Firstly, while the demons are summoning troops (and they will be), the Elves, with their incredible initiative and attack power, manage to eliminate half of the demon army.

Secondly, the succubi won't even have time to move, as the Elven archers usually go first, and of course, one of their primary targets will be the succubi. After that, the demons will have very few archers left.

Besides, no self-respecting player will leave archers alone and unprotected. There will definitely be Ents in front of them, and someone else on the side. In general, neither the jumping demons nor the Cerberi have any chance of causing any harm to the archers (this assumes that the player has the Tactics skill, which is one of the most important skills that the High Elves should take).