Zayne Carrick Vs Kanan Jarrus Vs Cal Kestis

Zayne at the beginning of the KotOR series

Kanan at the beginning of Rebels

Bracca Cal

All Out Fight 

Takes place in the Jedi Council Chamber

Which Padawan takes it

Kanan>Cal>Zayne imo

Kanan at the start of Rebels still has huge difficulties in the Force due to cutting himself off from it for years and his own fear, guilt and self-doubt. He might be able to pull a win but by the skin of his teeth. It's more likely Cal beats him.

Zayne probably most likely to survive, because the force actively wants to keep him alive and basically gives him in-universe plot armor, in a non-serious fight maybe Cal