As per usual there are a lot of people who do not understand possession stats and how that correlates to winning hockey games.
Player A is a fast footed, quick thinking, puck moving defenseman. He rarely turns the puck over, when he is on the ice his team tends to move from defense to offense. His corsi and fenwick numbers are high, as are his zone finish stats. Because his team spends comparatively little time in his own end when he's on the ice, the other team takes few shots, and thus he blocks few.
Player B is a heavy footed dullard who "clears the crease" really well and lays down facefirst in front of every shot he sees. He can't handle the puck well and his outlets are usually just chips off the boards that the other team picks up in the neutral zone. He leads the league in GRIT which consists of HITZ + BLOCKZ
Player A is the better defensive player, period.