2. Rangers. If their bonus was larger (and I think this should be taken into account), they would be in first place. Best stats, poison, first attack - no retaliation (invisibility). Besides, the start is very easy thanks to them.
Compared to them, assassins with their huge penalty for ranged attacks are...

It's easy to counter invisibility. As soon as rangers or Nightblades become invisible, they don't stop being vulnerable. Meteor Shower, Fireball, or, at worst, Stone Spikes, and everyone - both invisible and "visible" - will have a bad time.
If they managed to move around. If there's Meteor Shower, it's not a problem. It will definitely hit the rangers.
If there's no Meteor Shower, but there's a "large" creature with high speed, then the number of tiles it can move through will be reduced. You approach the area, and the invisibility is broken. Then it's just a matter of technique.
I have always believed, and continue to believe, that ranged units are better than melee units, because while the latter reach the former, the former will have time to shoot them three times (unless they are black dragons, whom they won't be able to hit, or Djinn Sultans or Paladins, whom they can only hit once). And if the ranged units are also protected by melee units...
The penalty of half, of course, changes things a bit, but if the enemy gets closer, or the hero has a unicorn horn bow (poor creature:D), then the enemies (including the rangers) won't have time to say "Why weren't we ranged units???" Besides, human and elven archers don't have a penalty.

7. Warrior Skeletons and Peasants. No comment. ...

The exception is bone warriors. They have "Large Shield," so they take even less damage and have good defense. These skeletons are more useful in their advanced form.
I already wrote about peasants. They're not such a bad unit. (P.S. The hero who gets more money from peasants is called Ellaina).

6. Goblins. Bonus. They may be the weakest individually, but in an army during a serious battle, due to their frenzy, due to the "Rage of the Horde" ability, and in general, they are one of the most effective units for the orcs. Anyone who has played a duel for
Shak'karukat will agree.

Maybe, but I'm terribly annoyed by their fleeing instead of counterattacking. And with blood levels, only "Betrayal" is removed.
Shak'karukat, as far as I remember, plays for Wyverns :confused:, and Keegan - for Goblins :confused:.