I tried using submunitions to attack ground units, but they caused no damage and couldn’t destroy any of them. However, they worked as expected against other types of targets, such as facility units.
So, is this determined by the unit’s armor type? That seems a bit inconsistent. For example, the ground unit type of the PHL-03 shows its armor as “Light (Handgun Resistant),” while the facility type shows “None.” Yet, the ground unit can’t be destroyed by submunitions, while the facility can. Similarly, towed artillery in the real world should be vulnerable to submunitions, but in CMO, a ground unit type like the M114, which is listed as “Light (Assault Rifle Resistant),” still can’t be destroyed.