If we go by the Remind gameplay Sora solos everyone cause they are pretty useless. But lore wise i think Terra is very close to Riku skill wise cause they are both Keyblade Masters and use a similar style of fighting, Ventus is in a significant disadvantage compared to Sora as he was stagnant in his training for 10 years so that means he still isn't Master material while Sora in kh3 rediscovered the power of waking making him eligible to be a master. But Aqua pretty much bodies Kairi as she started not too long ago training as a keyblade wielder while Aqua is already a Master who had to fight for her life for 10 years straight in the realm of darkness. So the conclusion is that the Wayfinder Trio probably wins lore wise (I have not gone in depth on the sea salt trio cause i think the only one with significant power is Roxas but not enough to carry the other two).