Maybe ask your FC how they feel about WAR, do they already have WARs (you said they were tank heavy)? If they don't you might ask them if they would find it better to have more options. I hear they're actually better for T4 off tanking because they're better at generating AoE threat (although it's still doable with 2xPLD). War brings a DPS/Threat boost for the PLD so that can be helpful. And eventually they'll probably add a boss or 2 where the WAR heal debuff will be desirable.

And if they're feeling creative, they might try WAR as a DPS option. Sure it does less DPS, but it's also sturdier and thus requires less attention from the healers (if there's lots of AoE damage going around). You'd probably need to get some DPS centric jewelry for this, however.