Well, the set can win that matchup if you are already set up at +2 and you predict a switch in to Heatran correctly (and he doesn't sacrifice a mon to bring him in safely), since:
+2 96 Atk Tough Claws Mega Charizard X Dragon Claw vs. 252 HP / 0 Def Heatran: 144-170 (37.3 - 44%) -- 100% chance...