Looking back at my notes I might have buggered that a bit. But you get the gist.
If Armour is present, defenders use their Hard Defense # (First number). A white # means it cannot be used for offense.
Combined arms attacks and choosing which unit to attack with makes a very big difference. That and being able to use units tht have not moved yet OR who have moved in the subsequent combats mixes things up also in terms of the sequence you move force in.
This provokes a little more depth than the typical I need 20v 5 for 5:1, and X # of drms.