Posts from Which level 1 monster do you like the most in Heroes of Might and Magic V?

The Assassin is the strongest, but the bonus is small.
Dryads are weak, but they are not targeted, and they attack up to 3 creatures at once.
Imps are optimally balanced; they are useful (they steal mana) and not that weak.
Imps are the best.

I completely agree. IMP is the best. The "mana steal" ability is very useful, sometimes even decisive in battle. And it's not bad in general.

This only helps against Imps at the beginning of the game, when the enemy hero is still weak. They steal mana only once, and then they rush into battle and are crushed by assassins. First, use poison, and then engage in melee combat; then nothing will remain of the Imps.

Yes, assassins are undoubtedly stronger than Imps, but you forgot that at the beginning of the game and later, there are never more than a hundred assassins, while you can gather about 300 Imps. And first, summon them near the assassin (Hell Gate), and then, while he's dealing with that, run up...
Ranged units have always been weaker than melee units in a one-on-one fight. Their strength lies in the fact that they are convenient for fighting neutral creatures and dumb computer-controlled heroes.

In my opinion, Dryads are better, especially if there are many of them, a strong hero, and the enemies are clustered together; they become a truly devastating force...