Below are the different strategies against Emperor Frederick.
Frederick's attacks are not too hard to evade if you have a good defense. Swordsmen are the only hard troops, which may cause some problems. Fortunately they are slow. Mostly the swordsmen will also advance to the walls, so pitch and killing pits may help. Archers and crossbowmen are both needed, but fire ballistae and mangonels should hold off the attackers. If he has knights assisting his group, assassins or macemen should be used.
Having a moat will reduce the danger from his attacks, as only his archers can fill it in, and these are easily killed.
Frederick is relatively easy to beat in the very beginning, since he is way much dependant on weapons production. Even if he manages to build his entire castle, you would not have to face heavy resistance. Choices:
- Rushing: Frederick starts out with a low number of troops, which he cannot reinforce quickly. Use this to your advantage. Killing off the crossbowmen on the ground is not hard and swordsmen require only a handful of troops to sacrifice. Don't attack from the front as this area is usually better defended, instead attack from the sides (if his position on the map allows this)
- Sieging: A bunch of catapults, fire ballistae and macemen are needed. Catapults should target towers with high priority, while fire ballistae remove defenders. Ballistae do incredibly well against mangonels and crossbowmen, since they recieve little damage from them. They are also useful when the keep's troops are needed to be killed. When no defenders remain, macemen should then make short work of the Lord, rushing in before he can create more troops.
Frederick does not buy in weapons or armor. Destroying his armory with a trebuchet will prove catastrophic to him, especially if it is full of weapons, as he will struggle to recruit more troops. However on the other hand, not buying in weapons will mean Frederick will have more money to spend on rebuilding walls and towers during a siege. Therefore a large, constantly moving, group of horse archers (100 to 150) will prove very useful as his walls and towers will be useless with no troops remaining.