Ok, I'm a total nub but which would be a *second* enhancing earring?
I remember seeing it, but someone else would have to point out the exact item. I think it's an augmented earring?
His Zenith crown is augmented with enhancing +8, too... so he'd be losing 12 enhancing over the chance of +2 proc, which I remember reading somewhere (Cant remember source right now or how accurate it was so I might be really wrong) that going for a steady number on enhancing was better than hoping and praying for a set +2 proc :3
Ignoring the earring:
Estimated AF3 proc rate with 2 pieces: 2%
Estimated AF3 proc rate with 4 pieces: 7%
Expected gain: 5% damage nullification
Reduction in damage taken (1000 baseline): 50
Tradeoff: 8 skill from zenith, 5 skill from hands for 13 skill. Additional resistance accrues at +1 for every 4 skill (for over 300 skill), which means that +13 skill is worth +3 resistance, maybe +4. Will be generous and use +4.
For nominal m.acc rates of 50% or higher, that would effectively be -4% hit rate. For nominal m.acc rates below 50%, that would be -2% hit rate.
The lower the nominal hit rate, the more valuable the reduction in hit rate from the higher resistance. Looking at the best case values, then:
Estimated average damage (to 4 resist levels) taken from a 1000 damage nuke
@54% nominal: 699.336
@50% with increased resistance: 664.063
Net reduction: 35.274 (3.5% of baseline)
@22% nominal: 352.312
@20% with increased resistance: 324.800
Net reduction: 27.512 (2.75% of baseline)
Clearly that's a worse option than the AF3 set, which should give a 5% reduction from baseline (or 4% at worst, depending on which version of the rates you believe) from wearing two additional pieces.