Actually, no offense to Beelzebub (although I'm guessing someone with the user name "Beelzebub" isn't easily offended), but "warrior" isn't quite right. Only straight Fighters, and Fighter kits, can exceed two proficiency points in a weapon. Rangers and Paladins are warriors, but they're not Fighters, so they can't gain mastery. (And, no, multi-class Fighters like Jahiera can't gain mastery either...bitch, ain't it.) The reason you can put three points in Minsc's dual-weapon style is because Rangers get a free point in that style, enabling them to go up to three stars.