Code Geass: Boukoku no Akito 1 - Yokuryuu wa Maiorita, 86 Recommendations
The overall settings and plot of the series really remind me Code Geass OVA: Akito the Exiled:
* discriminated soldiers from another nation/race
* spider like mecha/drones
* kindly female commander
* indoctrinated "republic"
* nicknames of both units are related to Ghost/Death
Very, very similar premise and setting
-Setting of war
-The pilots of the mechs are discriminated against
-Sympathetic female commander
-Mysterious Ace pilot who dominates the battlefield
-Similar mechs in the shape of spiders
Both main characters are very similar: Leila and Lena are commanders who cares about their armies, Akito and Shin are silent and telented militaries. Also, both are war themed with some racial questions.