I cant tell whether BI is better as I havent played on 1.5 much. I do remember that in 1.2 (and also in my one 1.5 campaign) I didnt get many naval invasions, in my Arverni-BI campaign Carthage is attacking Tolosa (Toulouse, France) every 2 years. Note that they have yet only expanded in Africa, their armies come from Algeria and Balears. Crete and Rhodos (including Pontic invasions) as well as other Islands and coasts suffer from naval invasions all the time etc.