As a Jedi Guardian who has heavily been playing pvp I can say I get slaughtered by Sith Sorcerers when there is more than one of them..
But that's the thing, the real problem is an unfair distribution of classes because of how people want to play; honestly this can't be helped.
I swear one game I played had like 5 Sith Inquisitors, mostly Sorcerers, 1 Bounty Hunter and 1 Sith Warrior. That's alot of Lightening and Stuns, and my stun break ability (Resolve) has a slow 2 minute cooldown...
Useless when I break out of a stun and get stunned again.
My 2 cents.