As I see it, Path of Fate (R2), allows you to spend WP to avoid damage taken, meaning actual damage that you would have taken otherwise (after armour and all that).
My reasoning for this is that a champion relies on his faith, it is not something he does, it is not a parry with shield or a weapon. His faith (whatever god he believes in) let him avoid damage. Will his faith also possible stop your armour from being damaged in the attack by removing all damage so you don't have to break your new nice looking armour with an armour roll. A fighter with the talent Path of the Shield (R3) can decrease the damage with his shield, but this is something he do (he parries) and is something that happens before the weapon even hits the armour.
A fighter is better fighting humanoids, multiple of them even. A champion is better fighting one enemy at a time, monster even.
This is just my opinion. The rules are in beta and this things are better reported in. FL has been known to lurk here every now and then so there is a good chance that they know about this thread and if the talent do work like the Path of the Shield (by removing potential damage before the armour roll) then they hopefully have time to clarify that before the release of the final pdf.
Yeah a fighter with path of the enemy could destroy a champion. I dont think the path of fate protects the armor though , if wp is applied after armor 1s on armor roll would still be in effect since it goes though .
1. Enemy hits character
2. Charcter roll armor, soaks some or all. If not all damage, 1s are breaking down armor
3. Character applies wp to soak up remaining dmg