It would seem that grouped units no longer act as a single large unit and losing members results in a stat change, I am glad this was done, unfortunately, I think there's been a mistake with the math for tactical combat. I haven't tested attack yet from fear of sudden death, but the defense is working backwards. For example, I attack 9 grouped darklings with a total defense of 40. At first everything in my army can hit it, including my sovereign with his attack of 6, then, as the numbers go down, it gets harder and harder to kill until a single unit is left with 30hp and is near unkillable and only groups of 8 archers can manage to hit it. While taking down the first 300 took only 2-3 minutes, taking out the last 30 takes me 10.

Thanks for the new unit stack system, it is awesome, there's just this little thing that needs addressing I guess.