You really don’t. You can cast shield of the righteous pre-combat with no target if you want. Bit of a waste of HP to do so but it does not require a target and no Prot Paladin abilities require an enemy in melee range.
I’m going to go against the grain here and say brewmaster. Funnest tank for me by a mile, and I played all of them except prot warrior (for now)
Windwalker and mistweaver are also pretty good for BGs. You probably dont care to heal but mistweaver is fairly easy to pick up and reaaaally good in BGs and Epic BGs. WW’s mobility and ports make them good objective players and can burst healers/kill targets in team fights
It’s in a rough spot for sure but idk worth trying imo if you dig it.
If not, druid is the best fit for your requests (boomy and feral SLAY in bgs or epic bgs). I’d place DK second.