Wargaming will never 'prove' anything or predict an outcome with certainty. It is merely a means of studying a problem and highlighting or exploring important issues. It will never be a substitute for actual operational experience.
There is more to modern war than combat War in the computer age includes everything from industrial mobilisation to combat logistics. Wargaming can simulate the full range of operational aspects of war (in air warfare this means prosecuting the three campaigns - control of the air, bombardment and support for combat forces) and the sustainment aspects of war (including command, control, communications, intelligence, training and logistics).