This was the federation answer for an urgent need for weapons against the Zeon offensive. Nothing more than a work pod with a gun stuck on top, these things were just cannon fodder for Zakus. But I suppose the Ball was cheap. Tactically, the balls give ranged support to the GMs. Hordes of GM and Balls overwhelmed the fortresses of Solomon and A Bau A Qu. After the OWY, balls are phased out of the Federation military though some can still be seen in use as late as 0083.