So, for single target main tanking,
5% dodge chance + 15% more Death Coil DMG, 15sec less CD on DND, 10sec less CD on DG, 3% strength and 2% more hit
is more valuable than
3% miss chance + 20% more IT DMG, Killing Machine, 25% haste melee, 4% strength and 20% melee haste raid buff?
And why do u spec into 10% more atk power aura when u have a hunter for that??? Or they are just not skilled enough? What if u have to tank phisical realm and FDK is inside the shadowrealm? What if FDK dies from infest or gets picked by a valk that drops him? What if he DCs?
My last atempt to try and explain this to u...
U wont ever do DND as a main tank, u hardly ever have the chance to use Death Coil, u wont EVER Death Grip a boss, and u most sertainly dont need extra 10 range to tank.
BUT
More melee hits = More Killing Machine procs
More Killing Machine procs = Higher Threat
More DMG on IT = Higher Threat
More Melee hits = More Rune Strikes = More Threat
Higher Threat = More Death Strikes
More Death Strikes = More Self healing
More Self healing = Good Blood tank.
If FDK dies u still bring 20% melee haste to the raid buff table.
If u have both 10% atk power and 20% melee haste auras and insane amount of aggro generated u can get some other DPS more valuable for 10m raid comps instead of FDK and a HUNTER if needed.
FUN FACT: Melee hits generate threat. Melee hits are ur top dmg done.
Do u even understand how VALUABLE Killing Machine and Glacier Rot are? U basicly cast DOUBLE IT and every 5th normal IT is an extra IT? Death Strikes and Self Healing is all that BDK tank has, the more u do it the better it is. How often do u even use Death Grip, DND, Death Coil when u tank bosses? How much hit do u even have?
ITEMIZATION.
Cloak 44hit, Ring 55hit, Gloves 69hit, Legs OR Helm 85hit, total of 253 hit.
U can also use Cryptmaker for total of 352 hit rating which is 13.42% spell hit.
On top of that u can use couple of 10hit10stamina gems to reach 14% hit which is more than enough with a shadow priest in a raid for example. So again u DONT need full 3/3 Virluence.
And even if u reach only 10-11% spell hit total (talents not included) u wont miss every 2nd Icy Touch, u will miss 1 out of 10 Icy Touches, or even less.
http://imgur.com/a/e6Gy0
2 posible item builds.
One with Glorenzelg works better on curent state of warmane since u can cap expertise with 22 rating. If expertise was Retail Like, it would be pointless using any Expertise items as a tank since u cant EVER cap it, so it all goes to RNG.
313 hit = 11.93% spell hit chance
348 hit = 13.27% spell hit chance