That has not changed in its functionality.
In the users manual is detailed how the combat is resolved. As I have said, there are many factors that we have to take in to acount when we go to battle, many of them very familiar with other games, terrain, weather, trench level, morale,... other are Ageod ones, the cohesion, the abilities of the commanders and that of the units, the combat attitude, ammo supply, and the frontage (really important to understand this if you want to get a full understanding of how battles are performed).
Said this, the engine calculate round after round what units are really taking part on that combat round, and wich of them fire on the enemy (you can see in the log folder the complete detail of what has happened but its not firendly to read a txt file), and depending of the troop quality, and other factors of the unit, you achieve an impact in the enemy unit you are firing to, you can also miss the shot. But if the unit hits the enemy then some health and cohesion damage is done.
In the report you can see for each round of combat the total hits in health and cohesion and the detailed for each unit, damage done and received and several events happened to each unit during combat (lucky if firing, morale check failed, crossing a river, entrenched, if the unit has killen an enemy subunit,...)
So we have a lot of information, maybe is not quite easy to understand but there is.
Sometimes happen that you lose a battle but you suffer few casualties, even less than the enemy. This is not so nice, because you claim the victory! but this means the enemy hold the ground, or you commander stopped the attack.