@Jhenna0
This item is objectively worse for you in your role as fury dps.
The Signet gives (30*1.2)*1.97+308/108*3 = 79.475 AP
(1.97 is the strength to AP conversion at that level, 1.2 Improved Berserker Stance, last term is Armored to the teeth)
The Tuskring gives 64.
That makes a difference of 15.4755 AP
Let's compare that with the expertise Rating. For that we look at the skill skaling for each stat at that level.
All skills 25.2 Exp equals to +1% damage
Autoattacks 17.9 Exp equals to +1% damage, 39.2 AP equals to +1% damage
Bloodthirst 22 AP equals to +1%damage
Whirlwind 39.9 AP equals to +1%damage
Slam 44.1 AP equals to +1% damage
Execute 65.2 AP equals to +1% damage
Overall, equipping the Signet over the Tuskring would mean
Autoattacks -0.33% damage
Bloodthirst +0.18% damage
Whirlwind -0.12% damage
Slam -0.16% damage
Execute -0.27% damage
Given the skill distribution over the total damage done (Whirlwind does the most damage total) and the Damage per Rage ratio (Bloodthirst having a 30-40% worse ratio), your overall damage will decrease if you equip the Signet over the Tuskring.
@comlogo
I would like to get into trouble with you, if you know what I mean ;).
@thyonem
The rules state that ninja rolling in this case is defined by needing on items that does not fit your role or is not needed to fulfill that role better. He was dps and he should not need tank items (without asking, most people don't mind).
@Glader
No, you are wrong. There is no inbuild roll system that restricts based on stuff you need.
There is just a restriction based on armor classes (cloth, leather, mail, plate). That's why warriors can NEED on spellpower rings and resto druids are not able to NEED on cloth items.