based on my other topic about giant skull, I started considering this (2 soc helms to get good survivability AND dmg in PvM, especially ww barb);

Good blood helm (high deadly strike roll, eg. 8-10 %) and 2 socs would potentially outperform Guillaume in geneal usefullness? (I personally see the CB overrated if the dmg per 1 hit is high enough otherwise already; exception might be bosses in high player count games)

But how many crafts would take per 1 roll with 2 socs? I think this is what it gets to even consider this helm over guillaumes, even thought it is possible with high DS roll AND life + resses this could become useful even with 1 soc

Takes probably in the thousands

Crit from mastery is probably 31% (lvl26 to 30)

Total DS from core items:
Grief 20% DS
HL 37% DS
Gores 15% DS
20+37+15=72% total without helm

100-72=28
0.28*31=8,68=8
72+8=80% crit chance without helm

If you add 10% DS from blood helm
100-82=18
0.18*31=5.58=5
82+5=87% final

If you add 15% from guillaume
100-87=13
0.13*31=4,03=4
87+4=91% final

Skills lvl 29 + most pts invested in str + might merc ‎ =  around 1100% off-weapon ed for WW (this is what I have on my build without any ed% on gear).
If we compare both helms above with my setup:
Guillaume 91% DS and 55%ED (including 15str)
55/1100=0,05
Vs
Blood helm 87% DS and 80%ED
80/1100=0,0727
This is only 2,27% more dmg from the extra 25%ED
This is not enough to compensate for the 4% dmg loss from less crit chance, without even talking about the massive 35% CB.

I guess, if your blood helm is absolutely GfG and offers more survivability, it could potentially allow you to dump more hard points in str, potentially to a point where they reach the same dmg (if we exclude CB). But it’s absolutely impossible for it to reach the same final effective dps. And trying to compensate with more str without getting the extra DR% and mdr like you could get on VampGaze is really not as good either, because the lower your life, the more you need of these 2 stats to be able to at least survive a burst of dmg before you leech back to full.

Blood helms are good if you need Visio and plan on using the 2 sockets mostly to either fix your IAS or get more DR%.
But they’re really far behind in terms of dmg, never a good option for PvM, even if you could afford a 100% perfect roll.