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o_O and are you saying that everyone is playing as mages? That's quite a statement. I didn't even like playing as mages in Heroes 5 because any magical faction (Dark Elves, Necromancers, Mages) is weaker than a warrior faction (Humans, Inferno, Elves – I'd also include Dwarves here; Orcs are just cannon fodder, as are Necromancers). In this game, mages are practically useless because spells are on cooldown, and a mage without spells is like a warrior without an army. And a warrior's army is always stronger due to superior stats like defense, attack, morale, and luck. I've always played as warriors in Heroes, and in Heroes 6, there's no question about it – mages are just too weak, and there isn't much magic anyway.
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And I'd also add that, in my opinion, the strongest faction here is the Orcs (it's hard for me to admit that Orcs can beat both Humans and Necromancers). However, the two most popular factions in Heroes 6 are Necromancers and Humans (both have warrior heroes). By the way, I recommend playing a large map as the Orcs.