By Michael Pina The Boston forward talks about who he models his game after, his toughest assignments and more. Grant Williams entered the playoffs as an intelligent, versatile defender who attempted and made more threes in his third year than in his first two combined. He was all-around solid enough, as a 23-year-old seventh man on a serious title contender. Fast forward to today, and Williams is integral, averaging eight more minutes in the postseason than he did during the regular season. (Only 11 players have logged more minutes overall.) He’s also shooting 41.9% from behind the arc on nea…