I'm playing as Prussia, I'm fighting Courland, and it's happened at least 2 or 3 times now: I'll spend an extremely large amount of money replenishing my units after a battle, then I wont notice until the next battle, but all my line infantry are cut in half to 60!? (Large unit sizes = 120). I was besieging Courland and when they finally attacked, I noticed the balance of power meter was slightly in their favor when all they had was like 5 good units and a bunch of armed citizenry.

Is there a plague or something? Is there something I'm missing about the replenishment mechanic? I would swear to you that those units were replenished to 120 men. What the heck is going on?