Im not a sofisticated ProtPala in PvP, but Arena and BattleGrounds are 2 different things.
A ProtPala in BattleGround is a support character. Buffs, Heal, Stuns. You are there to stun the healer that can save someone, or protect a good DPS who is ganked. I saved lots of Flags transporters with a stun and heal, or dispeling a slow.
Some fights can last 60 seconds, thats 2 stuns, some heals, 2 dispell slow debuff... In Lordaeron I kill a few, but saved a lot. If you want to go and kill, well, not. If you play for the objetives, its not the BIS, but you had fun with a good team.
2v2 or 3v3 right now with the crossrealm its retri or healer.