An adult Orca alone already significantly outclasses a Great White. A large adult Great White might weigh up to 1,110 kg (2,450 lb) while a large adult Orca can weigh up to 5,380 kg (11,860 lb). Orcas can reach speeds of over 48 km's per hour, while a Great White Shark manage up to 24 km per hour. The Orca's spine and tail also allow it to pull manoeuvres (sudden dive, climb) that a shark can't respond to. And that's before you even consider the Orca's brain...
And it seems Orca's may have figured out a sharks big weakness... tonic immobility - https://www.sharktrust.org/tonic-immobility