Nomads are preferable to harpies because they have much higher hit points, damage, and movement. But harpies may be preferred over nomads because nomads' weekly growth is lower than harpies (6 and 8, respectively ), so it's easier to create a large army of harpies than nomads.
Harpies have better defense, but they also have lower hit points than nomads. Harpies also have "strike and return" and "no retaliation" abilities, which when combined are better than the nomads' "First Strike" ability.
|Berserker · Centaur · Nomad · Harpy · Ogre mage · Cyclops · Thunderbird · Behemoth|
|Mermaid · Sea monster · Frenzied gnasher (WOW)|