Well i started on that server (vallon zek is the one with teams) and currently have a level 10 wrrior, i chose warrior because starting from scratch with a caster is not gonna be easy on my lil' newbie bank, i enjoyed playing the warrior and currently have 2 PKs under my belt hehe, from my experience on the server an enchanter or a necro are great classes to play on that server (had to zone away 5 times from 1 chanter 2 levels lower than me) but thinking about it i regret startin a warrior, i made 250pp in my first 2 days hunting spiderlings for silk and setting up a trader, the economy is different over there and i could get away with selling spiderling silks at 12pp a shot!! So without any twinks whatsoever i have a nice set of SVMagic jewlery and some decent plate armor to whack elves with hehe, i am on the blue team (my char is a vah shir)and that seems to be the largest team around.
Having said all of this i only have my char at lvl 10 so im not an expert on PvP Teams hehe