First, because of practical problems, wars don't happen every day, and ordinary people have no chance to test their war ability. This is different from modern times, and the current simulation technology is far from ancient times. Therefore, what was taught in ancient military schools was mostly an armchair strategist. You don't know who is ambitious! Most people who have the opportunity to practice are behind the door, and the emperor will not just hand over the military power to the door.

Second, it is not safe. If there is a vicious person, it will last for three or five decades. Who can guarantee that the next emperor can control his disciples?

Therefore, ancient times were not suitable for running schools jointly! ! ! !