The Mazinger Army in Mazinger Edition Z! is a squad of robots under the employment of the Photon Power Laboratory composing of Lori & Loru with their Million, Shun Azuma with his Baion, Masao Oide with his Daion, and Sayaka Yumi with her Aphrodite A. With the revelation of Koji with his Mazinger Z, they mainly act as back-up units.
We first see the Mazinger Army battle the Mechanical Beasts in the first arc with Koji still getting used to Mazinger Z. When Koji got the Z they work together to stop the Mechanical Beast invasion. However when Juzo dies from an injury caused by Baron Ashura's troops, Koji tries to kill Ashura only to be held back by the Mazinger Army hoping to capture him. But that fails and so Koji and the Mazinger Army go on bad ends.
After that Koji doesn't get along with the group in future battles seeing the army as weak imitations of the Mazinger, believing the genuine Mazinger Z is unstoppable and has no need of help. In another battle with Baron Ashura, where Koji and Sayaka are captured, the army comes with the Jet Scrander to save everyone from sinking. After this, Koji starts to appreciate the group better.
In the final battles Prof. Yumi upgrades their machines and manage to mass produce them creating an actual Mazinger Army. They were successful on destroying all remaining Mechanical Beasts but were no match when Hell King Gordon arrive. One by one the 3 squads were defeated by Dr. Hell's largest robot, Hell King Gordon but this was all part of Tsubasa Nishikiori's plan as every single one of them contains a Rocket Punch for Koji to use his 100 Rocket Punch attack to successfully finish off Dr. Hell. However this was all in vain as a new threat arises with his death.