Here's what I'd like to see done for Fending accessories:

*Make a VIT:STR ratio of 2:1 and make Slaying accessories available only to jobs with STR as their main stat.

Here's what I'd like to see for tanks jobs, in general:

*Make VIT affect enmity generation (tanks only) and parry/block rate and effectiveness (up to about 50% damage)

*I agree with the idea of making Sword Oath flip VIT/STR values (Defiance/Deliverance effectively does this anyway, so no change is needed there), though that may be trickier than Cleric Stance due to HP drops.