Eli5 why are combat units “ineffective” after taking 15% losses?

Question

Eli5 why are combat units “ineffective” after taking 15% losses?

In: 1029

Answer 1

A combat group is more than 50% support units and less than 50% actual gun/tank toting fighters. The losses are almost entirely actual gun/tank toting fighters. So a 15% loss is more like a 30% loss in fighting soldiers.

Plus, there are usually more injured than killed and that takes way more support than healthy troops.