Was tanking VR today (first time) and we had three tanks, druid, and 2 prot warriors, ( I am prot warrior), the prot warriors have slightly different talents , gear and enchants.
Job as you probably know is to make sure the tanks are above the dps threat, we all were , MT Druid at 200k, Prot War 1 at 190k, Prot War 2 (me) at 125k, nearest dps was at approx 90k ish.
embarrasingly for me and on view to everyone else through Omen I was at the end of the fight 70k threat behind the other Prot war, I have never had a problem holding threat, nor here but it worries me a bit seeing that in this fight.
Now I have very similar gear to Prot War 1, infact I would say I have better gear, though our talent trees are different, the enchants are too i.e. executioner for he, and mongoose for me, I have higher armor and health too, and can take a lot more damage, but struggle somewhat for rage.
Rotation is Dev, Dev SS Rev though I never seem to have enough rage to dump HS.
70K is a big diff IMO, so can slight talent tree changes and a few enchants and the odd piece of gear really make such a big diff for threat.
He has more hit and more expertise than you which can certainly translate into more threat over the course of an encounter. Also for VR it's going to really depend on how many knock backs each of you took. If you have a WWS of the fight I can look at it closer and see why, but just from armories, it's honestly really hard to tell. When I was doing this fight I typically went into full threat gear. Around 16% dodge and 17% parry, 14% crit, 140ish hit(Used hit food). Can't remember what my expertise was at the time to be honest. Executioner also does help a good deal.
I must say in my when we first started VR I had one hell of a time to get the tanks to realize that full tank gear is not ideal . When I tank him I make sure I keep my 490 def rat and after that I have all damage gear on with max hit and expertise .
But in a general view some threat stats that you must look at is as Danach mentioned hit and expertise and SBV ( GAB trinket imba ) 95 is the minimum reccomended hit rat for tanking with 142 odd as the hit cap (9%) while only using 1 weapon , on the expertise side I don't know the exhact numbers but I know after 6.5 % dodge is taken out of the equasion and on 15% expertise is capped ( very difficult to cap this ) .
Some gear suggestiones to improve threat ( and sorry didnt take the time to look at armory ) is the helm , boots and chest from ZA ( nice balanced gemming and SBV ) the belt and legs from the new SSO badge vendor ( imba hit and expertise) . The new badge chest is very nice if you are struggling with mitigation so in my case very situational so not a reccomended first buy imo . The old 60 badge gloves and the phalanx bracers are allso quite nice to balance out that threat and tanking stats . Oh and allthough executioner is a nice enchant , the proc agility and haste of mongoose makes mongoose a much better tank enchant imo .