You use two distinct game mechanics: players physically moving models on the tabletop, and abstract di(c)e rolls, to accomplish the same result. Why?
Allow me to answer this with a quote from my own post:
This keeps a balance between complete control and the random-ness of combat.
It also differentiates between what the player can control, and what the pilots themselves are capable of. If it was all down to the player like in Wings of War, pilot quality wouldn’t matter. If it was all down to the pilot quality, player skill and decisions wouldn’t matter. So I opted for a balance between the two.
Tom Jensen - http://ostfrontpublishing.com/