Not generals, but heroes. There's a small chance bowmen, longbowmen, crossbowman and artillery can reach hero status for excelling and battle in become William Tell. When they join your artillery, it becomes 10% more effective. The same for the foot soldiers: recruits, militia, soldiers & elites. Their hero is Leonidas.
And for cav, the hero would be called Pulaski.
Also, these heroes can die. So you better double check that block or you're going to regret it for weeks.