Buff Sicilians

Well, bad monk tech tree is just historical reason? Good monk tech tree usually given to civ with stick to one religion and famous for religious belief (e.g. Saracens, Teutons, Spanish). And Kingdom of Sicily was multi-cultural nation accept both Muslim and Christianity. There is not much historical justification to give good monk tech.

I don’t think it is ideal to give back seige bonus. Then they will win every mangonel war and huge advantage in treb war. It is crucial for high level play.

Their bonus purposely huge effects on their cavarly. Norman was good at cavarly(knight), and success on their battle against Berbers/Saracens (Camel). FE team posted historical justification of Sicilian bonus.
The History Behind the Sicilian Civ Bonuses - Age of Empires II: DE / II - Discussion - Age of Empires Forum