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

In my opinion, the easiest opponents for demons are mages (they have very low defense; in a game against this faction, you don't even need to summon reinforcements – nightmares, dogs, and archdevils will eliminate half the army), Dungeon (although it really depends on how much mana the warlock has left), Necropolis is roughly equal, and orcs are definitely stronger, but there are more demons. It's also difficult against humans. I have no idea how to defeat dwarves with demons; they are just too tough. There's also no chance against Haven. In general, demons are a pretty strong faction (they're definitely not an underdog), but they can't be called super-uber either.