Archers are a support unit - their purpose into the late game isn't to do damage, it's to set the egg on fire and buff your other units' damage. That said, if you throw 20 goblins at evolving them, their damage is respectable.
Wizards were the ones I found massively underwhelming. They do damage comparable to base soldiers, but don't have an upgrade/evolution path. Once you get berserkers, everything else is irrelevant in terms of damage - I had my 10 archers just focusing on setting the egg on fire, and then converted all my soldiers into berserkers. Nothing else could compete with that damage output, as far as I could tell.