I had the same problem as you at first. I would not be able to see the effect of my combats through the combat screen. However, I did figure out how to compensate for that. First of all, I can see the readiness/morale/entrenchement factors right on the enemy units (if my recon is high enough, and it will be if I bomb the hex with air). I can go to the stat window and choose any type of unit I want and see how many I killed (total) for the turn (or all turns).
A given combat for me starts with an air attack, to loosen up the defenders a bit and to get a high recon value on the hex. I then decide on which artillery I will bombard with. I will then examine the defenders to see if I really want to attack or not. In particular, I check the Readiness and Entrenchment levels. If I deem them low enough, I then attack without exceeding my stacking point limit.
After retreating the enemy, I will then try very hard to attack those retreated units again. Even if I have to play a speed card. Their morale will be lower, their readiness will be very low, and they will have little or no entrenchment. I call this the double-tap, and it will usually result in broken and panicked units.
If not, then I will decide if the enemy is strong enough to counterattack if I take the hex..if so, then I will not bother advancing. If the hex contains terrain, I will take it (with fresh troops if I can) and play an entrenchment card to dig in.
Anyways, the information you seek is fairly easy to find, you just wont see it 'on the fly' while you attack.
“My logisticians are a humorless lot … they know if my campaign fails, they are the first ones I will slay.” – Alexander the Great