Cabbe, Kale, and Caulifla all have great potential. Vegeta noted himself that Cabbe's base level was near his own during the Champa Arc, and this was after Vegeta's training with Whis. Caulifla was able to unlock Super Saiyan and Super Saiyan 2 within minutes of each other. And Kale's beserker mode shot her up to a level beyond's Caulifla's Super Saiyan 2.
All that being said, the Saiyan hybrids have all been stated to have enormous potential as well; more so than their full blooded Saiyan fathers. Gohan, Future Trunks, Trunks, and Goten all reached the Super Saiyan forms as children; though Goten and the current Trunks were much younger. We've also seen Gohan and Future Trunks power levels rise dramatically in Super, and they were able to do it in rapid time.
Out of these two groups; one being the Universe 6 Saiyans and the other being the Universe 7 Half Saiyans; who has the most potential?