Which class can best hard carry a trio?

If the other two in your comp's class can vary and they are still struggling in PvP, what class would you say can typically carry the best in trios?

Is it cleric for the heals, Rez or joining melee with smite?

Druid for the heals and shape shift options?

Barb to just tank and obliterate people?

Ranger for the added DPS at range and up close?

Plate Fighter with a bow for tank and ranged DPS?

A godlike wizard?