The army is fine; that's how it's designed (so you don't show up with a huge army and one-shot him).
Will they give me an army out of thin air, with which I can easily defeat him?
By the way, yes, I arrived without an army.
What's the point of such a thing? Otherwise, a boss for a quest shouldn't be considered a challenge if they give you an army to defeat him. With such an army, you can defeat him without any effort.