Overkill

From Supreme Commander Wiki

Overkill refers to damaging a unit by far more than its hit points. It is a waste of a weapon's capabilities, because the weapon could instead attack another target that has much higher hit points.

For example, one bomb from an Aeon T3 Strategic Bomber does 3450 damage. It is overkill to use this to destroy an enemy Tech 1 mass fabricator, which has only 360 hit points. It is more effective to use an Aeon T1 Attack Bomber, which does 200 damage and will destroy the target in 2 passes.

An example of what is not overkill is using a nuke on a large army of ground units. Although a nuke does 70,000 damage while the toughest non-experimental, non-command unit is the Percival with 9,300 hp (at the very least an overkill of 60,700 damage), the nuke's area of effect and inability to be defended against by anything in the field is something that cannot be duplicated by any other attack and the strategic gain is considerable.