Especially in the early part of the game, it's quite possible for a general to get 500-600 kills if you let it happen. The general will have all these stars and some upgrades and experience, and the enemy troops are cheap spearmen, peasant archers, and such. Often, the general's entire bodyguard will die and it's just him alone doing all that killing. This can be a real nightmare.... Hope you had a recent save before this happened :D