sometimes it is quite difficult to manage "aggro" (both in pve and pvp).
in pve the mobs will follow some obscure target routine, with alesia being on top of the list all the time...
there seem to be some speels that casue you to aggro more than others. ->wards are one of them IMO... my earth mages get constantly aggro'ed by mobs if i put them on the ground(they even leave alesia alone!); but thats a good thing for an earth mage.

it would be nice to be able to do a bit more aggro managment with warriors though..
same applies for pvp.
warriors are often sinply ignored, and all storm for the monk if there is one (a stupid strategy IMO... but thats another topic).
so my suggestion:
>>>>>>>>>
"Taunt & diversion"
You insult and irritate the enemy so much, he has difficulties to focus on the the target you are protecting that way.
If he turns on you he will be somewhat in rage though...
Atribute: Tactics
Stance
Adrenaline Cost: 3
Duration: 1 minute
Effect: All weapon based attacks on targeted ally player do (15...25)% less damage. All weapon based attacks on you do 20% more damage.
>>>>>>>>>
there should be some visible indication of the protected, and the protecting players. or it could even be group based...
the long and set duration forces you to live with the drawbacks, once casted.