Damage Distribution???

How does damage distribution work?. for example let's say I have 2 infantry and 2 armored cars. since I have 2 infantry and 2 amoured cars that means that the damage distribution will be 50/50. if I were to face 4 ordnance artillery by it's self. how would the damage distribution work. Since ordnance artillery is good against light armour would it deal the most damage to the armored cars. or since it's 50/50 would the damage be spread out thus every unit Taking the same damage? I have asked this in chat multiple times and no one has responded if you were to help me i would appreciate it.