Um... have you ever played EU3? This is not how this ends in EU3. In EU3, you beat the enemy stack to the province they're retreating to and then the enemy stack is automatically obliterated when it arrives because it has to fight a battle at 0 morale. In EU3, and especially multiplayer. big, decisive battles are typically fought with what we call "doomstacks." If your main stack was routed by a doomstack, then nothing else you have nearby is going to be of any help. Attrition was an annoyance at best. It never stopped anyone from dropping a 40K stack onto the front lines, even in the 5.2 beta with the new manpower changes.