Below are different strategies against The Pig.
The Pig uses fast macemen, rendering ballistae and mangonels useless. However, they will stop when they start removing walls. A good number of crossbowmen are the key here, along with some fire ballistae. They can deplete their health very quickly and they work quite well against siege equipment too. Hostile crossbowmen are also removed before they can even sling a shot on you. If the macemen reach your walls, placing slingers alongside your archers or crossbowmen on your walls is surprisingly effective in dealing with them. A few fire throwers scattered along your walls, protected by archers or crossbowmen can also prove effective.
If you have a good sized group of horse archers, send them outside the castle to fire arrows at the Pig's macemen while they are waiting to attack. Macemen are relatively vulnerable to arrows.
The stronghold of the Pig is easy to siege. A good number of fire ballistae can remove the crossbowmen or use mass catapults to crumble the few towers and the gatehouse he has. Mass horse archers work too, but they are likely to suffer high casualties from the penetrating bolts. After the exterior is cleared, light up buildings so the macemen will trap into the flames. One or two dummy units may draw macemen from the keep, to maximize efficiency. Then you should perform an easy kill. Don't use Arab swordsmen, even at this late stage as if the Pig manages to create a few crossbowmen for his keep, they will suffer high casualties.