I haven't done a ton of pvp's on my pally + 4x shammy team.
The pally is dual spec and one of the shammies is dual spec.
The other three shammies are elemental spec with a pve focus.

Pally has PvE Prot and PvP Prot/Holy.
Shammy has PvE elemental and PvE resto.

For PvE play I usually run PvE Prot + 4x Elemental.
Occasionally run PvE Prot + 3x Elemental + 1x Resto.

For PvP play, I run PvP Prot/Holy and 4x Elemental.
I got the spec on arena junkies.
It's mostly Prot, but the talents are a bit different, and the Holy goes a little deeper.
http://www.wowarmory.com/talent-calc...00000000000000
Suggested Glyphs were: Flash of Light, Seal of Wisdom and Avenger Shield.
This is a healer spec, with healer gear.

I've got Grid + GridCustomLayouts + Clique, which will allow me to click cast on unit frames.
My shammies cast at the target of my paladin, but with this route, I can for example Alt Left Click on a frame, for Flash of LIght, without changing my target from what I want the shammies to burn down.
I figured I could not force hordies to attack a tank.
But my healer could be very hard to kill with tank talents.